Adjuvant: A chemical added to a vaccine to boost immune response to an anti- 
genic component. 
Adverse effect: An undesirable, usually serious complication probably caused by 
the administration of a vaccine or a drug. 
Adverse event: Any undesirable experience that occurs in a defined period after 
the administration of a vaccine or a drug. The vaccine or drug does not have 
to be the cause Of the event. 
Anaerobic: A bacterium that grows in the absence of oxygen (e.g., the bacterium 
that causes tetanus or botulism). 
Anaphylaxis: A serious, life-threatening reaction. In hypersensitive individuals, 
anaphylaxis has causes as diverse as bee venom, peanuts, shellfish, and anti- 
gens In some vaccines. 
Animal reservoir: Species of animals that can be infected by a virus that also 
infects humans so that the virus cannot be eradicated. 
Antibody: A protein molecule (immunoglobulin) produced by B cells in response 
to a specific antigen. 
Antibody titer test: A laboratory procedure for determining the strength Of anti- 
body production against an antigen. 
Antigen: A nonself molecule that induces an immune system response. resulting 
in the production of antibodies. 
Antigen-presenting cell: An immune system cell that engulfs a pathogen and 
then exhibits some of the pathogen's protein on its surface so that the antigen- 
presenting cell looks like a foreign cell. Macrophages and dendritic cells are 
the major antigen-presenting cells. 
Attenuated: Said ofa whole virus or bacterium that has been grown under adverse 
conditions or chemically treated so that it is weakened to the point where it 
does not cause the diseuse but stimulates an adequate immune response to it. 
B cell: An antibody-producing cell that is part of the adaptive immune system. 

Background rate: The frequency with which an adverse event occurs in an 

unvaccinated population. This rate is compared to the frequency of the same 

adverse event in a comparable vaccinated population to help determine if the 

vaccine causes an increase in occunence of the adverse event. 

Biologic product: A medical product made from natural sources such as human 

Or animal cells, or microorganisms. 

Blood serum: The clear yellowish fluid that remains after blood cells and clotting 

factors have been removed from whole blood. 

Bone marrow: Soft tissue that fills the hollow spaces of bones. Red bone mar- 

row produces stem cells that become erythrocytes (red blood cells), lymphocytes (white blood cells), and platelets. Yellow bone marrow produces stem 

cells that become fat, bone, and cartilage. Red and yellow bone marrow exist 

within the same bone cavities. 

Clinical trial: A research study using humans in which volunteers are assigned 

to various groups to test the safety and effectiveness of a drug before it is 

licensed for public use. 

Clonal expansion: The ability of a cell to divide and create millions of identical 

daughter cells. 

Cold chain: A continuous system of cold boxes, refrigerators, and freezers used 

to keep biological products such as vaccines within a narrow temperature 

range during transport, distribution, and storage to prevent loss of potency 

of the product. 

Cytokines: Small signaling proteins released by cells that control the behavior of 

other cells and help mediate the immune response. 

Encephalitis: Acute swelling and inflammation of the brain that can result in 

permanent brain damage. 

Formalin: A solution of formaldehyde and water. 

Guillain-Barré syndrome (GBS): A rare syndrome in which the immune system 

attacks healthy nerve cells resulting in weakness or tingling sensations that 

move up the body and can cause paralysis. GBS appears to increase after 

infection with the Zika virus. There has been some controversy over whether 

influenza vaccination also increases the incidence of GBS. 

Hematopoietic stem cells: Stem cells in the bone marrow that have the potential 

to differentiate into many different types of blood cells. 

Herd immunity: Also called community immunity, this condition occurs when a 

high-enough percentage of the population is immune to a contagious disease 

through vaccination or naturally acquired immunity that there is little oppor- tunity for the disease to spread to nonimmune individuals. Immune tolerance: The ability of the immune system to recognize and leave unharmed an individual's self cells while attacking foreign cells and material. Immunity: In medicine, the ability of an organism to resist disease, usually through the development of antibodies against the disease-causing pathogen. In law, exemption from certain legal proceedings, such as being sued Or pros ecuted for a crime.

Secondary response: Stimulation of antibody production by memory cells on re- 

encountering a pathogen, usually taking two to seven days. Rapid secondary 

response is the basis for active immunity. 

Spleen: The largest lymphoid organ in the body. Located to the left of the stomach and below the diaphragm, it produces lymphocytes (white blood cells) 

and removes old and damaged red blood cells from the blood. 

Stabilizer: Substance added to a vaccine to shield it against temperature changes and to maintain its potency and extend its shelf life. 

Subunit vaccine: A vaccine made by identifying and isolating the pathogen's 

antigenic proteins without including any of the pathogen's genetic material. 

T cell: One of several related cells that mature in the thymus and help direct the chain of reactions that result in adaptive immunity. 

Thymus: A butterfly-shaped lymphatic organ essential to the production of 

T cells. It gradually decreases in size after puberty. 

Vector: An organism, often a biting insect or tick, that transmits a disease from 

one animal to another or from an infected animal to a human. 

Zoonoses: Diseases that normally exist in animals but that can be transmitted to humans and cause illness, 

Zostavax and Shigirix

Shingles

 Shingles, also called herpes zoster, is caused by a reactivation Of varicella zoster, the same virus that causes chickenpox. Chickenpox symptoms disappear within about two weeks. However, the varicella zoster virus enters nerve cells where it remains inactive, Often for as many as 30—40 years. If the virus is reactivated, the individual develops shingles. The mechanism for reactivation is not well understood, but it appears to be connected to weakening of the immune system. Most shingles develop in people over age 60 years. although the virus can reactivate in much younger people who are immunocompromised (e.g., HIV infected; receiving chemotherapy). Shingles is a painful but not life-threatening disease. The first sign is itching, burning, or a painful sensation on the skin. This is followed in one to five days by a rash that usually develops only on one side of the body. The rash is accompanied by pain and often headache and low fever. The rash evolves into fluid-filled blisters that crust over in about two weeks. About 20 percent of people who develop shingles experience long- lasting pain called postherpetic neuralgia (PHN) so severe that it interferes
About 20 percent of people who develop shingles experience long- lasting pain called postherpetic neuralgia (PHN) so severe that it interferes with activities such as bathing, dressing, and sleeping. Pain usually is in the area where the rash was present and can last for months after the rash disappears. As of 2()18, there was no treatment for PHN. About 15 per- cent of people who develop shingles have blisters in the eye area. A few of these people develop permanent vision deficits. About one in three people will develop shingles during their lifetime. An estimated 500,000 to I million cases occur in the United States each year. People who live to age 85 have a 50 percent chance of developing shingles. Most people have only one outbreak, although repeat outbreaks are possible, especially in immunocompromised individuals. Shingles is not contagious; it cannot be passed from person to per- son. However, if a person who has never had chickenpox or has not been vaccinated against the disease comes into direct contact with fluid from shingles blisters (e.g., a grandparent with shingles holding a child not vaccinated against chickenpox), that person may become infected and develop chickenpox. Administration of Shingles Vaccine Until 2017, there Was Only One shingles Vaccine, Zostavax, approved for people over age 50 years in the United States. Zostavax contains the same live attenuated virus as varicella vaccine given to prevent chicken- pox, except that the shingles vaccine is 14 times stronger than the dose given to immunize against chickenpox. In October 20 1 7, a second shingles vaccine, Shingrix, was approved by the FDA and recommended by ACIP for adults over age 50. Shingrix is a recombinant subunit vaccine derived from genetically engineered Chinese hamster ovary cells. It requires two doses, the second two to six months after the first. The original shingles vaccine, Zostavax, is just over 50 percent effective in preventing shingles, but it is 67 percent effective in preventing PHN. In clinical trials, Shingrix, was just over 90 percent effective in preventing shin les and reducing PHN for at least four ears. As of 2018 the CDC
was recommending revaccination with Shingrix for individuals who were originally vaccinated with Zostavax, as well as vaccination with Shingrix of all unvaccinated individuals over age 5() years. Adverse Effects Both shingles vaccines cause mild adverse effects. The most common are transient pain, swelling, itching, and redness at the injection site, and muscle ache or headache. A few people vaccinated with Zostavax develop a mild rash. Special Populations Certain medical situations may change the recommended administration of shingles vaccine. Individuals should discuss any conditions that may alter use of shingles vaccine with their physician.
Zostavax contains gelatin and the antibiotic neomycin. People who have had a severe allergic reaction to either of these or other vaccine components or to chickenpox vaccine should not be vaccinated with Zostavax_ Shingrix does not contain either antibiotics or gelatin. People who have diseases and disorders that compromise the immune system (e.g., HIV infection), are taking immune-suppressant drugs, have certain blood and lymph cancers, or are receiving chemotherapy
\or radiation should not be vaccinated with Zostavax and should dis- cuss advisability of vaccination with Shingrix with their physician. • Moderately or severely ill individuals should wait until they are healthy to be vaccinated. • Individuals who are certain they have never had chickenpox or have never received a vaccine against chickenpox should not be vaccinated. What Makes This Vaccine Controversial? Shingles vaccine is not controversial except for individuals who reject all vaccines. However, many older people skip this vaccine or are unaware of it.

pneumovax 23 and Prevnar 13 the confusion

I am always a little unsure about these 2 vaccines 
so here is a cheat sheet 


Pneumococcus Currently there are two recommended vaccines to help prevent pneumococcal dis- ease in older adults: the Pneumovax 23 and the Prevnar 13. The most common presentations of pneumococcal disease are pneumonia, sepsis, and meningitis. In 2014, the Advisory Committee on Immunization Practices (ACIP) recommended that the Prevnar 13 be used as a first-line immunization in person's age 65 and older who had not previously been vaccinated against pneumococcal disease, to be followed 12 months later by the Pneumovax 23. Similarly, if a patient has previously been vaccinated with Pneumovax 23, it is recommended to administer the Prevnar 13. The Prevnar 13 should be given no sooner than 6—12 months after the Pneumovax 23. The Prevnar 13 has been reported to be 45 % effective in preventing invasive
 pneumococcal disease in patients over 65 [121. Prevnar 13 is a conjugate vaccine while Pneumovax 23 is a polysaccharide vaccine. Prevnar 13 protects against the 13 strains Of pneumococcus that are most frequently seen in the elderly population. The Pneumovax 23 protects against 23 strains, but seems more effective when given in a series with the Prevnar 13. The main contraindication to vaccination with Prevnar 13 is an allergy to diphtheria vaccine. Contraindication to Pneumovax is an allergic reaction to prior Pneumovax vaccination. Both vaccines can cause some swelling, redness and tenderness at the injection site that usually resolves within a week.

THE UNIVERSE

THE UNIVERSE
 Sometimes I wonder!

Do any of these leaders of the world, Trump,Xi,Modi etc etc, ever  stop to ponder the vastness of the universe and how insignificant  the Human race is, how infinitesimally small they are in comparison to their Blown up egos

In the vastness of the Universe. the Earth. the Sun and planets are tiny dots. The Sun is a single star in a galaxy comprising 100.000 million stars. At least as many thousands of million of other galaxies. each with its own star system, extend as far as the largest and most sophisticated of optical and radio telescopes can reach. As the Universe expands. all galaxies clusters of galaxies move apart from each other at speeds that depend upon their distances. The furthest ordinary galaxy yet detected. Abell 1835 IR 1916 is 13.230 million light years away and is receding at 45 Percent of the speed of light. The most distant object in the Universe as on July 14.2004 is in background of Abell 2218. This corresponds to a distance greater than 2 billion light years. Beyond this, astronomers are looking back to a time when the Universe was born. and the Universe fades out.

Galaxies are dotted like islands throughout the Universe. A galaxy .is a huge congregation of stars which are held together by the force of gravity. They are so Sig that/sometimes they are called Island Universes. Most of the galaxies appear to be scattered m the space in a random manner. but then a.ec many galaxies which remain clustered into groups. the smallest are poor clusters Of only a few dozens galaxies. while the largest rich clusters may contain thousands of galaxies. Our galaxy. the Milky Way, is part of a poor cluster of about three dozen galaxies called 'the local group 
The largest member of the Local Group is the Andromeda galaxy. and the Milky Way second largest galaxy in this group: most of other galaxies in our Local Group are small. The most distant objects in the Local Group are M31 , the Andromeda galaxy and M33, all of them being more than 2 million light years away from our galaxy.
Hubble thought that galaxies might evolve from elliptical into spiral form as they age; but astronomers today do not believe this to be true. Galaxies range in Size from small dwarf elliptical ones. with perhaps I million stars. to spiral galaxies containing 300 billion stars. to giant elliptical galaxies that may home to more than 10 trillion stars. The diameters of the galaxies range from light years in dwarf elliptical galaxies to over 50.000 light years in giant elliptical galaxies.

The nearest star is about times farther away than most distant planet in our solar system. A few ofthe other larger objects found beyond Pluto are Varuna (2000), Ixion (2001 Quaoar (2002), and Sedna (2003).
pearson's General Knowledge 2009

Nikolai Vavilov an enemy of the people ?

 But apparently Vavilov was too important a figure. After the war broke out in 1941, Vavilov was thrown into prison in Saratov.. .. On January 26, 1943, the scientist who had probably done more in his life than anyone else in the country to prevent humanity from suffering famine, died of hunger in a prison cell.. .the Soviet regime declared [Nikolai] Vavilov an enemy of the people, his name was erased from all printed sources, and his works were banned. ... Nikolai Vavilov's name was cleared, and his works began to be published again in the country in the 1960s. But the harm to Russian agriculture had been done and could not be reversed. The postage stamp illustrated here was issued in the Russian Federation in the year 2000 to commemorate the pioneering work of Nicolai Vavilov and his discovery of the law of biological variability in 1920. Bolotovski et al. (1998) analyze in detail the historical data including quotations from those who knew Sergei Vavilov to ascertain how Sergei could manage to continue to work diligently toward the creation of a national physics research institute of world renown for a government that, in the short period of only three years, had unjustly imprisoned and taken the life of his dear brother. They quoted Nobel Laureate Andrei Sakharov (1921—1989) who commented

I had an appointment with the FIAN director, a prominent optical physicist, academician Sergei Ivanovich Vavilov, who was a brother of another, even better known academician, Nikolai Ivanovich Vavilov, a biologist who had been arrested and died in prison a few years before. It was one of the most terrible pages in the tragic history of Soviet biology. [Sergei] Vavilov was soon appointed (or had already been appointed) President of the USSR Academy of Sciences. In this capacity he had to meet regularly (at least once a week) with T. D. Lysenko, an Academy Presidium member who had been a principle prosecutor of his brother, responsible for his death. I just can't imagine how he took these meetings... [Sergei] Vavilov was a nice person to meet, good hearted and gentle. He had placed a number of envelopes with cash in a drawer of his desk (his personal money) and he pressed on the destitute visitors these envelopes as in most cases he was unable to give them the support they really needed. The authorities learned of this and attempted to prohibit it...he carried out his duties without sparing himself.... As Academy President he often had to deliver official addresses. In one such speech he referred to Stalin as the 'Coryphaeus of Science' and this expression later became a part of Stalin's official title (apparently he liked it).

Sergei Vavilov used his position as President of the USSR Academy of Sciences to try to attain exoneration for his brother Nikolei. Bolotovski et al. (1998) note that in 1955, 4 years after Sergei died, V. F. Sennikov, a staff member of FIAN, examined documents in the archives of the Ministry of State Security with the purpose of rehabilitating the innocent victims of Stalin's purges. They note that Sennikov was "particularly impressed (by Sergei) Vavilov's letter of 1949 addressed personally to Stalin in which he appealed for the exoneration of his brother. The letter included a detailed account of the life and work of N. Vavilov, described his openness and honest and straightforward manner of speaking. Vavilov firmly rejected all subversive actions attributed to his brother claiming that the accusations against him were slanderous. Vavilov ended his letter saying "if my brother N. Vavilov is not exonerated, I cannot remain President of the USSR Academy of Sciences." They note that the letter bears an inscrip- tion by Beria "Not authorized", and that there were no marks indicating that the letter was shown to Stalin. As Director of the P. N. Lebedev Physics Institute and President of the USSR Academy of Sciences, Sergei Vavilov did all he could to help and protect staff and colleagues from Stalin's purges. There are numerous examples and the reader is invited to peruse the detailed accounts given by Bolotovski et al. (1998). The degree to which Vavilov played in the establishment of physics in the USSR is evidenced by the relatively numerous Nobel Laureates that emerged from the P. N. Lebedev Physics Institute, which he established from 1934 to the time of his death in 1951 and from the USSR Academy of S (19(
of Sciences over which Vavilov presided. Among these Noble Laureates are Pavel A. Cherenkov (1904-1990), Il'ja M. Frank (1908-1990), Igor Y. Tamm (1895-1971), Lev D. Landau (1908-1968), Aleksandr M. Prokhorov (1922— ), Nicolay G. Basov ( 1922— ), Andrei D. Sakharov ( 1921—1989) was awarded the Nobel Prize for Peace, Pyotr L. Kapitsa (1894—1984), and Vitaly L. Ginzburg (1916— ). A final example of the numerous cases where Sergei Ivanovich Vavilov tried to help fellow scientists within the stressful atmosphere of Stalin's oppression within which they had to live and work is taken from the life of Vitaly Ginzburg, who shared the Nobel Prize in Physics 2003 "for pioneering contri- butions to the theory of superconductors and superfluids." Vitaly Ginzburg did pioneering work on the interpretation of the VaviIov—Cherenkov Effect in collaboration with Il'ja Frank during 1939—1947. His contributions to the interpretation of the Vavilov—Cherenkov radiation did not begin to appear in print until 1940 in the Journal of Physics of the former USSR and in the Proceedings of the USSR Academy of Sciences some three years after the famous paper of Il'ja Frank and Igor Tamm (1937), which explained the radiation discovered by Vavilov and Cherenkov. Consequently Ginzburg did not share in the Nobel Prize for Physics 1958 with Cherenkov, Frank and Tamm. However, he was awarded the Nobel Prize for Physics 45 years later as noted above on a totally different subject matter. Vitaly Ginzburg provides the following account of Sergei Ivanovich Vavilov in his book The Physics ofa Lifetime (Ginzburg, I ) with kind permission of Springer Science and Business Media O Springer:

Give them Medals ! not suspend them

Hyderabad: 4 civic staff suspended for poisoning 78 stray dogs

The citizens of  Siddipetr should start a crowdfund to help them

Hyderabad: 4 civic staff suspended for poisoning 78 stray dogs

Hyderabad: Four municipal officials involved in the killing of around 78 stray dogs in Siddipet village, have been suspended after an FIR was registered against them.

A few days ago, 78 street dogs were poisoned and buried in the outskirts of Siddipet. This created an uproar among animal rights activists who sent a wave of messages to MP Maneka Gandhi, who is known to be a crusader for animal rights, and who apparently took up the matter with the authorities.

Ms Gandhi took to social media to share the action taken against the officials who killed the dogs. “As soon as we were informed, an FIR was filed. After persistent efforts, an order by the District Collector confirms the suspension of four officials from the Siddipet municipality,” she said.

She added, “40 more dogs were killed in Vikarabad, Telangana, by the municipality. The post-mortem results confirmed that the dogs were poisoned. The case was reported on 19th June, 2019 and an FIR was filed on the same day against the municipal officials responsible for this cruel act.”

Stray dogs may not be killed but must be sterilised under the Animal Birth Control Programme. One more hare brained ( I don't know if they find fault with this  phrase also) scheme  of  the  erstwhile minister

see this news :
I would call these people who were trying in their own  limited  means  to put an end to this stray/street/dog menace

Three-Month Old Infant Mauled To Death By Stray Dogs In Uttar Pradesh The incident took place in Dayalpur village in Behat area. The dogs picked up the infant, who was sleeping in a courtyard.
Outlook THE FULLY LOADED MAGAZINE

In a shocking incident, a three-month old was mauled to death by stray dogs in Uttar Pradesh's Saharanpur. The incident took place in Dayalpur village in Behat area. The dogs picked up the infant, Who was sleeping in a courtyard. On Tuesday morning, the mutilated body of the infant, whose head was missing, was found in the fields. In April last year, stray dogs had killed over a dozen children in Sitapur district. People have stopped their children form going to school and stepping out of the houses. Villagers are demanding a solution to the growing number of stray dogs in the rural areas. A special team was called in form Mathura to round up the dogs.

Did Darwin read Mendel?

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Did Darwin read Mendel? 
David Galton
QJM: An International Journal of Medicine, Volume 102, Issue 8, August 2009, Pages 587–589, https://doi.org/10.1093/qjmed/hcp024
Published: 13 March 2009
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Read no further if you want a definite answer to this question. It is a sort of detective story with clues scattered around. The circumstances surrounding the question however are so interesting since they involve two of the most important scientific publications of the 19th century.

The truly ground-breaking studies of Gregor Mendel were read before the Society for the Study of Natural Science of Brunn in 1865 entitled Versuche uber Pflanzen-Hybriden (Experiments in Plant Hybridization). Mendel ordered 40 reprints of his paper to send to famous European scientists; Darwin by then was certainly one of the most famous. Darwin's book on Origin of Species had been out for 6 years and was already in its 3rd edition. It had been translated into German, French, Dutch, Spanish, Polish and Russian.

Mendel had of course read and studied the Origin of Species in the German translation, Uber die Entstehung der Arten as soon as the second edition appeared in 1863. In his personal copy, he made many notes in the margin with his small and careful handwriting with double underlines of some of the text and even interspersed with the occasional exclamation mark. He bought most of Darwin's other works and studied them carefully making frequent annotations. So it would be natural for him to send Darwin, as an eminent English naturalist, one of his 40 reprints.

Of the 40 reprints of Mendel's article records exist that one was sent to each of the following scientists: von Marilaun, Kerner, Beijerinck, Boveri, Schleiden, and the Swiss botanist Karl Wilhelm von Nageli, now working in Munich. The last exchanged letters with Mendel over 7 years on the topic. More copies of the reprint were to be found in learned societies around Europe including the Royal Society, the Linnaean Society and the Greenwich Observatory in Britain.

Where were the other remaining reprints sent (about 29)? At the time Darwin's house in Kent was a sort of communication hub for European naturalists. Darwin was writing (and receiving) letters on a daily basis about issues and problems of natural history. If Darwin had received and read Mendel's article, he would have found a detailed analysis of the frequencies observed for different inherited traits from generation to generation of the edible pea. But these results were given in a mathematical form that might have put Darwin off from reading any more of the article. Darwin said that: ‘Mathematics in biology was like a scalpel in a carpenter's shop – there was no use for it.’ The concluding remarks of the paper made quite far reaching claims that the author had discovered laws that could predict the appearance of the different hybrid characters in successive generations of the edible pea, and that this would probably apply to other plant species. Of course it needed confirmation by further experimentation, but in view of the unity in the developmental plan of all organic life one may assume it to be correct. The final two paragraphs argued that the transference of characteristics amongst cultivated plants, such as the edible pea, can be accomplished and seems to occur by discrete integral steps which if accumulating in one species of plant could ‘transform’ it into a different species. Mendel's conclusions left no room for blending inheritance that Darwin believed to occur.

Darwin was usually meticulous in assimilating new material and making notes. He could read German slowly, a few pages at a time. He was already corresponding with several top European scientists who were working on the broad issue of heredity. There was Carl F von Gaertner in Southern Germany working in the small town of Calw and later in Stuttgart; August Weismann in Freiberg and also von Nageli. If Darwin thought German articles were important enough he would get them translated by William Dallas, a competent naturalist who often prepared the indexes of Darwin's books. In the case of Mendel's article, it was left to the Royal Horticultural Society to translate the work into English a few decades later.

Even if Darwin did not receive a reprint he had yet other chances to read of Mendel's work in the early 1870s. Hermann Hoffman, a Professor of Botany at Giessen had written a little book on plant hybrids in 1869 and on page 52 was a long excerpt from Mendel's paper of 1865. On Darwin's copy of the book (now preserved in the Cambridge University Library) are hand written notes in the margins by Darwin on pages 50, 51, 53 (facing page 52), 54 and 55. These are close to the citation of Mendel's paper but it may be that Darwin skipped over this passage or did not appreciate its significance.

Darwin had a further chance to read about Mendel's work in 1881. A student of his, George Romanes, was preparing an article for the Encyclopedia Britannica on plant hybridization. He enlisted Darwin's help to suggest names of eminent botanists who should be included. Darwin replied by sending Romanes a copy of a recently received book by Wilhelm Focke on the topic, published in 1881. Mendel's work was summarized on three pages (108–111) and the section ended stating that: ‘Mendel thought he had found constant numerical relationships between the different types of crosses’. But these pages were uncut in Darwin's copy and Romanes left them so. Mendel's name was included by Romanes in his article for the Encyclopedia, but he never read what Mendel had done.

Did Darwin miss the significance of this one jewel out of the many plant hybrid papers that were being published at the time? He could have easily checked the results for himself. Darwin had personally done and was still doing large numbers of plant breeding experiments using more than 50 plant species including the edible pea, orchid, snapdragon, flax, primrose, etc., but never with the idea of primarily studying the transmission of plant characters. He was more interested in the problem of hybrid vigour and its role for evolution. His main question was whether seeds from cross-fertilized flowers would produce superior plants than seeds derived from self-fertilized flowers. It seems he never thought of performing plant breeding experiments to check the results of Mendel, even though he had the required skill, knowledge, resources and the patience to do this sort of work. In his book on The variation of animals and plants under domestication (1868) he wrote that he had planted 41 varieties of English and French edible pea to study the extent of their variation. He observed the variations that Mendel had studied: smooth vs. wrinkled peas; tall plants vs. short ones; differences in flower colour, etc.; but he did not study any hybrids. However, he did do crosses using the common snapdragon with the rarer (peloric) form. In the second generation of hybrids that he obtained, he counted 90 to be the common variety (with two as an intermediate type) and 37 to be the rarer form. He thus obtained a ratio very close to 3:1; but he made no comments on this. Darwin was still thinking along the lines of blending inheritance where one would never expect to get constant ratios in the inheritance of parental traits. And he held this view until his death in 1882.

The unsolved mystery therefore remains: did Darwin actually receive a copy of Mendel's article? And if so did he bother to read it? A catalogue of Darwin's library from Down House published in 1908 (that is 26 years after Darwin's death) did not record any of Mendel's papers. However after Darwin's death in 1882 his scientific library passed to his son Francis. Down House was cleared of its contents in 1896 following the death of Emma Darwin and the house then leased to a school. Francis Darwin later bequeathed the library to the Professor of Botany at Cambridge University and a catalogue of the library was prepared by H.W. Rutherford (the one published in 1908). There was thus ample time for small items to go astray.

The catalogue did record the presence of Focke's and Hoffmann's books; and the former mentions Mendel's claim to have found ‘constant numerical relationships’ among the different phenotypes of the F2 generation of the edible pea.

Even if Darwin had received Mendel's reprint did he read it? He was not sympathetic to a mathematical presentation of data and Mendel's paper was full of algebraic reasoning. If he did read it there is no evidence that Mendel's analysis influenced Darwin's firmly held views on blending inheritance. This might have held up the progress of genetics for Darwin's colleagues in England (G. Romanes, T.H. Huxley, F. Galton, etc.) for at least two decades.

Further reading
Curt S, Sherwood ER. The Origin of Genetics: A Mendel Source Book. San Francisco, W H Freeman, 1966.

Henig RM. A Monk and Two Peas. London, Phoenix, 2001.

She writes that a reprint was sent to Darwin and she obtained her information about this from Anna Matlova, who was director of the previously named Mendel Museum in Brunn. Of course sending a reprint is not the same as receiving one.

Iltis H. Life of Mendel. New York, Norton, 1932.

Mendel GJ. Versuche uber Pflanzen-Hybriden. Verk naturf.Ver in Brunn; band iv 1865. English translation in J R Hortic Soc 1901 and in Bateson W. Mendel's Principles of Heredity. Cambridge, Cambridge University Press, 1902.

Olby RC. Origins of Mendelism. Chicago, University of Chicago Press, 1985.

Olby R, Gantrey P. Eleven references to Mendel before 1900. Ann Sci 1968; 24:7–20. This is a scholarly account of the uptake of Mendel's work before 1900.

Orel V. Gregor Mendel: The First Geneticist. Oxford, Oxford University Press, 1996.

© The Author 2009. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org