From John Denny 12 July 1872
Summary
Replies to CD’s queries. Duke of Cornwall Pelargonium is fertile with its own pollen. Has failed to produce hybrids from other varieties besides P. peltatum and P. elegans. Sends numbers of the Florist which contain an account of his mode of procedure ["On cross-breeding pelargoniums" Florist & Pomologist (1872): 10, 34, 50].
Reports a confirmation of his theory of the prepotence of the male parent.
| Author: | John Denny |
| Addressee: | Charles Robert Darwin |
| Date: | 12 July 1872 |
| Classmark: | DAR 162: 159 |
| Letter no: | DCP-LETT-8407 |
Matches: 9 hits
- … Pelargonium is fertile with its own pollen. Has failed to produce hybrids from other …
- … und künstliche Befruchtung durch den eigenen Pollen. Pt 1 of Beiträge zur Kenntniss der …
- … Pelargonium is fertile with its own pollen. With regard to the Ivy leaved sections, I have …
- … Thiselton-Dyer, about the relative size of pollen-grains in different varieties affecting …
- … CD had therefore studied prepotency of pollen from a separate individual within the same …
- … to fertilize Peltatum Elegans with the pollen of the wild blue geranium, & there are signs …
- … a variety of an ivy-leaved pelargonium with the pollen of a zonal; this was reported on in …
- … theory of the prepotence of the male (or pollen) parent, see Denny 1872b , p. 50, and the …
- … of Peltatum Elegans, by employing the pollen of a gold & bronze bi-color. To ascertain …
To John Denny 9 July 1872
Summary
Has read JD’s articles in the Gardeners’ Chronicle [(1872): 872, 904–5].
Questions him on the fertility of certain varieties of Pelargonium which are fertile with some varieties but infertile with others.
| Author: | Charles Robert Darwin |
| Addressee: | John Denny |
| Date: | 9 July 1872 |
| Classmark: | University of Otago Library, Special Collections (DeB MS 55) |
| Letter no: | DCP-LETT-8403 |
Matches: 6 hits
- … und künstliche Befruchtung durch den eigenen Pollen. Pt 1 of Beiträge zur Kenntniss der …
- … Cornwall Pelargonium fertile with its own pollen, as well as with that of the 2 or 3 vars …
- … the relative influence of the male (or pollen) parent and the female (or seed) parent on …
- … vars? Or is the Duke sterile with its own pollen & fertile only with certain vars? This …
- … leaved Pelarg. , besides Peltatum-elegans, with pollen of the Zonal, & have always failed; …
- … supposed distinct species as when the pollen of a zonal pelargonium fertilised a variety …
To John Denny 22 July 1872
Summary
Discusses the mutual sterility of some varieties of Pelargonium.
| Author: | Charles Robert Darwin |
| Addressee: | John Denny |
| Date: | 22 July 1872 |
| Classmark: | University of Otago Library, Special Collections (DeB MS 55) |
| Letter no: | DCP-LETT-8423 |
Matches: 5 hits
- … a stigma, already thickly coated with its own pollen: I know this experimentally, & in the …
- … case of Primula the second dose of pollen was put on after an interval …
- … of 24 hours— After a grain of pollen has remained on the stigma for about half …
- … all the contents have passed down the pollen-tube, I have found the detection of the …
- … excluded; but you might like to hear that the pollen of a pre-potent form will fertilize …
From John Denny 20 July 1872
Summary
Thanks CD for his offer to communicate the results of his experiments with Pelargonium to the Linnean Society. Prefers to continue experimenting for at least another season before doing so.
| Author: | John Denny |
| Addressee: | Charles Robert Darwin |
| Date: | 20 July 1872 |
| Classmark: | DAR 162: 160 |
| Letter no: | DCP-LETT-8421 |
Matches: 4 hits
- … in every instance, unless by using their pollen upon themselves or upon each other of …
- … virginity , viz, that there is not a grain of pollen on it; & I assume that as soon as …
- … covered it completely with the desired pollen, that it is proof against the receipt of any …
- … Society. I am this season putting the pollen of Peltatum Elegans upon the zonal section—& …
From Friedrich Hildebrand 5 February 1872
Summary
Praise for Descent.
| Author: | Friedrich Hermann Gustav (Friedrich) Hildebrand |
| Addressee: | Charles Robert Darwin |
| Date: | 5 Feb 1872 |
| Classmark: | DAR 166: 212 |
| Letter no: | DCP-LETT-8201 |
From George Sparkes 14 February 1872
Summary
Describes some crosses he has carried out with Primula;
mentions the infertility of cherimoyer [Annona cherimola] in England.
| Author: | George Sparkes |
| Addressee: | Charles Robert Darwin |
| Date: | 14 Feb 1872 |
| Classmark: | DAR 177: 223 |
| Letter no: | DCP-LETT-8213 |
To John Denny 14 July [1872]
Summary
Discusses JD’s crossing experiments with Pelargonium; notes that his conclusions on male prepotence oppose those of Gärtner. Suggests that his observations on differences in fertility of certain varieties of Pelargonium crossed with certain other varieties be communicated to the Linnean Society.
| Author: | Charles Robert Darwin |
| Addressee: | John Denny |
| Date: | 14 July [1872] |
| Classmark: | DAR 96: 114–15 |
| Letter no: | DCP-LETT-8410 |
To Hermann Müller [before 5 May 1872]
Summary
Comments on HM’s paper ["Anwendung der Darwin’schen Lehre auf Bienen", Verh. Naturhist. Ver. preuss. Rheinland 29 (1872): 1–96];
sexual selection in bees.
Encloses account on habits of Bombus.
| Author: | Charles Robert Darwin |
| Addressee: | Heinrich Ludwig Hermann (Hermann) Müller |
| Date: | [before 5 May 1872] |
| Classmark: | DAR 146: 433; DAR 194: 1; Krause ed. 1885–6, 2: 84–8 |
| Letter no: | DCP-LETT-8312 |
From Thomas Rivers 29 March 1872
Summary
Sends two vines for CD’s experiments, with instructions for grafting.
Mentions a hybrid plum–peach.
| Author: | Thomas Rivers |
| Addressee: | Charles Robert Darwin |
| Date: | 29 Mar 1872 |
| Classmark: | DAR 176: 173 |
| Letter no: | DCP-LETT-8259 |
Matches: 1 hit
- … was from blossoms crossed by my son with the pollen of the peach thus dropped off I have …
To Athénaïs Michelet 23 May 1872
Summary
Discusses books about cats and crosses in cats. Thanks her for her book on cats.
| Author: | Charles Robert Darwin |
| Addressee: | Adèle-Athénaïs Mialaret (Athénaïs) Michelet |
| Date: | 23 May 1872 |
| Classmark: | American Philosophical Society (Mss.B.D25.417) |
| Letter no: | DCP-LETT-8348 |
Matches: 1 hit
- … Müller crossed species of Abutilon , using pollen from two different species applied to a …
To T. H. Farrer 13 October [1872]
Summary
THF’s article in Nature ["The fertilisation of a few papilionaceous flowers", 6 (1872): 478–80, 498–501] is extremely good.
Suspects he now has answer to why common peas and sweetpeas hardly ever intercross, a point which half drove CD mad for years.
| Author: | Charles Robert Darwin |
| Addressee: | Thomas Henry Farrer, 1st baronet and 1st Baron Farrer |
| Date: | 13 Oct [1872] |
| Classmark: | Linnean Society of London (LS Ms 299/18) |
| Letter no: | DCP-LETT-8557 |
Matches: 1 hit
- … artificially crossed by removal of own pollen in bud, the offspring are very vigorous. …
From John Ball 31 January [1872]
Summary
Expands on a letter to Nature concerning the probability of the survival of a new variety in a given species. Differs with [F. Jenkin’s] argument, to which CD had agreed to a greater extent than JB feels it deserved.
| Author: | John Ball |
| Addressee: | Charles Robert Darwin |
| Date: | 31 Jan [1872] |
| Classmark: | DAR 47: 196–201 |
| Letter no: | DCP-LETT-8190 |
Matches: 1 hit
- … new variety would often be crossed with pollen from the unmodified form & that a portion …
| letter | (12) |
| Darwin, C. R. | (6) |
| Denny, John | (2) |
| Ball, John | (1) |
| Hildebrand, Friedrich | (1) |
| Rivers, Thomas | (1) |
| Darwin, C. R. | (6) |
| Denny, John | (3) |
| Farrer, T. H. | (1) |
| Michelet, Athénaïs | (1) |
| Müller, Hermann | (1) |
| Darwin, C. R. | (12) |
| Denny, John | (5) |
| Ball, John | (1) |
| Farrer, T. H. | (1) |
| Hildebrand, Friedrich | (1) |
Forms of flowers
Summary
Darwin’s book The different forms of flowers on plants of the same species, published in 1877, investigated the structural differences in the sexual organs of flowers of the same species. It drew on and expanded five articles Darwin had published on the…
Matches: 15 hits
- … male flowers on separate plants) and also noted that their pollen differed in size and shape. He …
- … of Primrose & Cowslip with short pistils & large-grained pollen are rather more fertile …
- … of my experiments lead me to suspect that the large-grained pollen suits the long pistils & the …
- … I think I have made out their good or meaning clearly. The pollen of A is fitted for stigma of B …
- … both terms referred to the fertilisation of one form with pollen from the same form. At this late …
- … two forms and that one of these was absolutely sterile with pollen from the same form, while the …
- … explained to Gray, ‘ I have lately been putting the pollen of the two forms on the division of the …
- … me as truly wonderful, that the stigma distinguishes the pollen; & is penetrated by the tubes of …
- … he told Hooker, ‘ In function, but not in appearance, the pollen of these two forms, as tested by …
- … is so frequent in truly hermaphrodite groups; namely the pollen & stigma of each flower being …
- … of the plant, with dotted lines indicating which pollen must be applied to each stigma to produce …
- … He told Gray in October 1865 that with respect to its own pollen, the long-styled form was …
- … plants raised from Dimorphic species fertilized by their own pollen, are themselves generally …
- … in a few specimens. It is necessary to compare size of pollen grains & state of stigma ’. …
- … ‘I will rank no plant as dimorphic without comparing pollen-grains & stigmas’. When Hermann …
Charles Harrison Blackley
Summary
You may not have heard of Charles Harrison Blackley (1820–1900), but if you are one of the 15 million people in the UK who suffer from hay fever, you are indebted to him. For it was he who identified pollen as the cause of the allergy. Darwin was…
Matches: 11 hits
- … fever, you are indebted to him. For it was he who identified pollen as the cause of the allergy, and …
- … 5 July 1873 Darwin wrote again, saying: ‘The power of pollen in exciting the skin & mucous …
- … changes in his own symptoms, that he was able to single out pollen as the only credible cause. …
- … He also experimented with fresh, dry and extracts of pollen, administered to his nose, mouth, eyes …
- … writes: Perhaps where grass is cut & dried; some pollen of the entomophilous division …
- … was fascinated by Blackley’s experiments testing whether pollen could be carried large distances in …
- … p. 5). Darwin gave a further example of how coniferous pollen could be carried for hundreds of miles …
- … with carbolic acid to deter insects. He concluded that in pollen seasons much higher levels were …
- … from hay fever in large cities far away from sources of pollen. In his later work, possibly …
- … Blackley tried to find out the smallest amount of pollen that would initiate and maintain the …
- … recommending spending summers in suitable locations to avoid pollen. But his lasting contribution …
Cross and self fertilisation
Summary
The effects of cross and self fertilisation in the vegetable kingdom, published on 10 November 1876, was the result of a decade-long project to provide evidence for Darwin’s belief that ‘‘Nature thus tells us, in the most emphatic manner, that she abhors…
Matches: 20 hits
- … flowers and the physiological effects of different forms of pollen. Although many plants that Darwin …
- … many of these were nevertheless fertile with their own pollen. He set out to compare several …
- … of the young plants when raised from a pistil fertilized by pollen from the same flower, & from …
- … that Darwin would confirm that this poppy shed its pollen immediately after the flower opened, …
- … since even those flowers to which he applied foreign pollen had probably already been self …
- … on which he commented, ‘This complete infertility with own pollen could hardly have remained …
- … you w d care, is that a great excess of, or very little pollen produced not the least difference …
- … On the other hand seeds from this plant, fertilised by pollen from the same flower, weigh less, …
- … beginning to suspect that the insects which could transfer pollen in sweet peas simply did not exist …
- … mignonette ( Reseda odorata ) was absolutely sterile with pollen from same plant in spite of the …
- … there sh d be some difference in ovules & contents of pollen-grains (for the tubes penetrate …
- … the same plant!’ ( To J. D. Hooker, 21 May [1868] ) Pollen tubes, or rapidly elongating vegetative …
- … ovary of a flower; they are triggered to elongate when the pollen touches the stigmatic surface. …
- … at the lessened fertility when he pollinated plants using pollen from other plants of the same …
- … the early part of the flowering season quite sterile with pollen from the same plant, though fertile …
- … as adults forever fixed in close proximity to others, so pollen from widely separated flowers could …
- … stylar forms of flowers, Darwin had referred to unions where pollen from one form had been applied …
- … that some forms were absolutely sterile with their own pollen while others had varying degrees of …
- … Ernst Haeckel, ‘It is really wonderful what an effect pollen from a distinct seedling plant which …
- … forms of flowers that showed sterility could exist when pollen from one form was applied to the same …
A fly on the flower: From Hermann Müller, 23 October 1867
Summary
In March 1867, Hermann Müller, a young teacher of natural sciences at a provincial Realschule (a type of secondary school that emphasised the natural sciences) in Lippstadt in the Prussian province of Westphalia, sent Darwin two papers on the mosses of…
Matches: 4 hits
- … order to observe their adaptations for collecting nectar and pollen. A letter he wrote in October …
- … of the hoverfly mouthparts that are specially adapted for pollen eating. Müller’s discovery seemed …
- … as pseudotracheae), which were the perfect size for holding pollen grains. He further noted, having …
- … in different species, depending on the size of the pollen eaten by each type of fly. It is amazing …
Floral Dimorphism
Summary
Sources|Discussion Questions|Experiment Floral studies In 1877 Darwin published a book that included a series of smaller studies on botanical subjects. Titled The different forms of flowers on plants of the same species, it consisted primarily of…
Essay: Evolutionary teleology
Summary
—by Asa Gray EVOLUTIONARY TELEOLOGY When Cuvier spoke of the ‘combination of organs in such order that they may be in consistence with the part which the animal has to play in Nature,’ his opponent, Geoffroy St.-Hilaire, rejoined, ‘I know nothing of…
Matches: 14 hits
- … meaning. One good illustration of it is furnished by the pollen of flowers. The seeming waste of …
- … ’ which every one has heard of. Myriads upon myriads of pollen-grains (each an elaborate organic …
- … a violet, in which there are not many times more grains of pollen produced than there are of seeds …
- … other flowers also, provided with a large surplus of pollen, and endowed (as the others are not) …
- … to certain insects, which are thereby induced to convey this pollen from blossom to blossom, that it …
- … of which are committed to insects, the likelihood that much pollen may be left behind or lost in the …
- … in orchis-flowers is accounted for by the fact that the pollen is packed in coherent masses, all …
- … against it when it sucks nectar from the flower, and so the pollen will be bodily conveyed from …
- … case, that of pine-trees, the vast superabundance of pollen would be sheer waste if the intention …
- … ’ as the means, no one is entitled to declare that pine-pollen is in wasteful excess. The cheapness …
- … involved in similar difficulty. The superabundance of the pollen of pine-trees above referred to, …
- … In the analogous instance of willows a diminished amount of pollen is correlated with direct …
- … difference in the conveyance would reduce the quantity of pollen produced. It is, we know, in the …
- … work and material; but why should it begin to produce less pollen? But this is as nothing compared …
Orchids
Summary
Sources|Discussion Questions|Experiment A project to follow On the Origin of Species Darwin began to observe English orchids and collect specimens from abroad in the years immediately following the publication of On the Origin of Species. Examining…
From morphology to movement: observation and experiment
Summary
Darwin was a thoughtful observer of the natural world from an early age. Whether on a grand scale, as exemplified by his observations on geology, or a microscopic one, as shown by his early work on the eggs and larvae of tiny bryozoans, Darwin was…
Hermann Müller
Summary
Hermann (Heinrich Ludwig Hermann) Müller, was born in Mühlberg near Erfurt in 1829. He was the younger brother of Fritz Müller (1822–97). Following the completion of his secondary education at Erfurt in 1848, he studied natural sciences at Halle and Berlin…
Orchids
Summary
Why Orchids? Darwin wrote in his Autobiography, ‘During the summer of 1839, and, I believe, during the previous summer, I was led to attend to the cross-fertilisation of flowers by the aid of insects, from having come to the conclusion in my…
Matches: 5 hits
- … puzzles me.— The Fly-Ophrys seems hardly ever to get its pollen masses moved at all, & the …
- … agency—another part, namely the natural falling out of the pollen-masses, being adapted for self …
- … in which I ask for information on what kinds of moths the pollen-masses of Orchids have been found …
- … Hooker, ‘ I shall never rest till I see a Catasetum eject pollen-masses, & a Mormodes twist its …
- … not only because of its remarkable ability to eject its pollen masses like a catapult, but also …
The evolution of honeycomb
Summary
Honeycombs are natural engineering marvels, using the least possible amount of wax to provide the greatest amount of storage space, with the greatest possible structural stability. Darwin recognised that explaining the evolution of the honey-bee’s comb…
Fool's experiments
Summary
‘I love fools' experiments. I am always making them’, was one of the most interesting things the zoologist E. Ray Lankester ever heard Darwin say. ‘A great deal might be written as comment on that statement’, Lankester later recorded, but he limited…
Matches: 1 hits
- … to Lankester involved placing under a bell jar some pollen from a male flower together with, but …
Darwin in letters, 1864: Failing health
Summary
On receiving a photograph from Charles Darwin, the American botanist Asa Gray wrote on 11 July 1864: ‘the venerable beard gives the look of your having suffered, and … of having grown older’. Because of poor health, Because of poor health, Darwin…
Matches: 4 hits
- … whereby each form achieved the highest fertility only with pollen from the other two forms. The …
- … collecting and measuring flower parts, drawing pictures of pollen-grains, stigmas, and anthers, and …
- … writing on 14 April [1864] , ‘I can do as much pollen work as ever you like’. Comments on William’s …
- … Crüger confirmed both his observation of Catasetum pollen adhering to a humble-bee’s back, …
What is an experiment?
Summary
Darwin is not usually regarded as an experimenter, but rather as an astute observer and a grand theorist. His early career seems to confirm this. He began with detailed note-taking, collecting and cataloguing on the Beagle, and edited a descriptive zoology…
Darwin in letters, 1862: A multiplicity of experiments
Summary
1862 was a particularly productive year for Darwin. This was not only the case in his published output (two botanical papers and a book on the pollination mechanisms of orchids), but more particularly in the extent and breadth of the botanical experiments…
Species and varieties
Summary
On the origin of species by means of natural selection …so begins the title of Darwin’s most famous book, and the reader would rightly assume that such a thing as ‘species’ must therefore exist and be subject to description. But the title continues, …or…
Scientific Practice
Summary
Specialism|Experiment|Microscopes|Collecting|Theory Letter writing is often seen as a part of scientific communication, rather than as integral to knowledge making. This section shows how correspondence could help to shape the practice of science, from…
Matches: 1 hits
- … fertility of orchids he has self-pollinated and crossed with pollen of other species. …
Scientific Networks
Summary
Friendship|Mentors|Class|Gender In its broadest sense, a scientific network is a set of connections between people, places, and things that channel the communication of knowledge, and that substantially determine both its intellectual form and content,…
Matches: 3 hits
- … He discusses how dipterous insects are adapted to eating pollen rather than only to sucking nectar. …
- … flowers. One is ripening. Dissection of the other shows the pollen accomplishes fertilisation …
- … interpretation of Acropera pollination is ingenious. Pollen-tubes of some cleistogamous flowers …
Darwin in letters, 1877: Flowers and honours
Summary
Ever since the publication of Expression, Darwin’s research had centred firmly on botany. The year 1877 was no exception. The spring and early summer were spent completing Forms of flowers, his fifth book on a botanical topic. He then turned to the…
Matches: 4 hits
- … . ‘I will rank no plant as dimorphic without comparing pollen-grains & stigmas’, Darwin …
- … and painstaking measurements of the size and number of pollen-grains, Darwin compared the fertility …
- … especially with the aid of insects: the size and shape of pollen-grains, the position of stigmatic …
- … life to which all organisms are subjected, by producing both pollen and seeds’ ( Forms of flowers …
A tale of two bees
Summary
Darwinian evolution theory fundamentally changed the way we understand the environment and even led to the coining of the word 'ecology'. Darwin was fascinated by bees: he devised experiments to study the comb-building technique of honey bees and…
Matches: 1 hits
- … is, depressing the keel so that the mechanism which caused pollen to be deposited on the bee would …
