To W. E. Darwin [14–17 May 1864]
Summary
Instructions on measuring pollen of dimorphic plants.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [14–17 May 1864] |
| Classmark: | DAR 97: A3 |
| Letter no: | DCP-LETT-4479 |
Matches: 9 hits
- … Instructions on measuring pollen of dimorphic plants. …
- … Down] P.S. I begin to think it would be far safer to measure pollen dry . Some time try …
- … not put thin glass over dry scattered pollen & secure thin glass over the slide by 2 …
- … Cowslip to be measured dry. — The Pulmonaria pollen looks very different size dry. — Look …
- … small grains of Pulmonaria angustifolia pollen, as CD had mentioned in his letter of 14 …
- … responded to CD’s request to observe the pollen dry in his letter of 18 May [1864] . See …
- … May 1864] . William had already sketched pollen for CD from the two forms of wild yellow …
- … CD had asked William to soak the yellow cowslip pollen the longest before measuring it; he …
- … For CD’s interest in the shrivelled pollen-grains from long-styled Pulmonaria flower-buds, …
To W. E. Darwin 3 May [1864]
Summary
Thanks WED for measuring cowslip pollen. Sends dimorphic flowers.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 3 May [1864] |
| Classmark: | DAR 97: A8, A10 |
| Letter no: | DCP-LETT-4480 |
Matches: 9 hits
- … Thanks WED for measuring cowslip pollen. Sends dimorphic flowers. …
- … any. Yours affect. | C. Darwin May 3 d . — You had better brush off the pollen. — P.S. …
- … Will you notice in the young anthers, perhaps pollen is shed whether there …
- … seems to be more pollen in the one form than in the other? — I am too bad to observe it. …
- … in 1863 and 1864, and measured the pollen of the red equal-styled cowslip in 1864 and …
- … for me. — Very many thanks for measures of pollen of red cowslip: I am very much surprised …
- … grew from John Scott’s plant resembled the pollen from the short-styled form but included …
- … p. 427. For CD’s general remarks on pollen size in heterostyled species, including …
- … 30 April 1864] and n. 2. CD wrote that the pollen of the equal- styled plants that he …
To W. E. Darwin [2–3 August 1862]
Summary
Discusses Lythrum, "a really wonderful case"; asks WED to make observations and collect specimens; sends a diagram which shows what crosses he believes are fertile.
Would like George to watch bees visiting the flowers; wants some pods from different forms to compare shapes and count seeds.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [2–3 Aug 1862] |
| Classmark: | DAR 185: 70, DAR 210.6: 102 |
| Letter no: | DCP-LETT-3678 |
Matches: 11 hits
- … must study it; the red lines show which pollen will fertilise which stigmas; all the other …
- … from each plant. — I noticed slight difference in pollen of long & short stamens in the …
- … difference between green & yellow pollen in the mid- & the short-styled plants. I wanted …
- … with little damp, not wet, moss) to compare pollens: I suspect those that go in pairs in …
- … camera in same position outlines of all six pollens, I would have them engraved from your …
- … three or more than three sizes & shapes. Pollen had better be dry ; it sticks to glass I …
- … how well corresponding heights will carry pollen on proboscis from flower to flower. Do …
- … return stamps. I am perplexed about pollen, & I believe I must measure all again distended …
- … of body did not abound with the green pollen & another part with yellow. Ask George to …
- … will see what I mean; it is like the two pollens of Cowslip on proboscis of moth & Bees. …
- … camera lucida drawings of the two sets of pollen from each of the three forms of Lythrum …
From Emma and Charles Darwin to W. E. Darwin [20 May 1864]
Summary
CD much obliged for specimen and drawings.
| Author: | Emma Wedgwood; Emma Darwin; Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [20 May 1864] |
| Classmark: | DAR 97: A7 |
| Letter no: | DCP-LETT-3366 |
Matches: 4 hits
- … styled Pulmonaria with own pollen …
- … William mentioned sending drawings of pollen and anthers, as well as a tin case enclosing …
- … The short-styled Menyanthes is fertile, I know, with own pollen, like the short- …
- … appeared to be sterile with its own pollen. However, in this letter, CD may be referring …
To W. E. Darwin [19 May 1864]
Summary
Mentions WED’s extraordinary discovery of some pollen-grains of different sizes. The observations must be followed up.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [19 May 1864] |
| Classmark: | DAR 210.6: 186 |
| Letter no: | DCP-LETT-5333 |
Matches: 4 hits
- … WED’s extraordinary discovery of some pollen-grains of different sizes. The observations …
- … 1 big anther with its differently sized pollen grains is a quite new & most extraordinary …
- … larger than all the others; but I never dreamed of the pollen-grains differing. Never mind …
- … or not search more flowers & measure pollen & keep memorandum how many times you succeed …
To W. E. Darwin 4 [July 1862]
Summary
Reports some observations on the fertilisation of wheat which WED might follow up.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 4 [July 1862] |
| Classmark: | DAR 210.6: 100 |
| Letter no: | DCP-LETT-3641 |
Matches: 7 hits
- … sketch-book (DAR 186: 43) contains a note dated 10 July 1862, describing pollen-masses …
- … and pollen tubes of ‘Grasses’. CD had been impressed by Karl Friedrich von Gärtner’s …
- … I observed in almost every one of the pollen-grains, which had become empty & adhered to ( …
- … branching hairs of stigma, that the pollen-tube was always (? ) emitted on opposite side …
- … of cells, of hardly greater diameter than pollen-tube:: I am astonished that the tubes sh …
- … specimen examined (not carefully by me) had pollen only during few hours on stigma; & the …
- … mere suspicion has crossed me that the pollen-tubes crawl down these branches to the …
To W. E. Darwin 14 May [1864]
Summary
Discusses WED’s observations on polymorphic flowers.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 14 May [1864] |
| Classmark: | DAR 97: A1–2, A4–5 |
| Letter no: | DCP-LETT-4495 |
Matches: 7 hits
- … originating from individuals producing less pollen in Forms of flowers p. 304. For his …
- … that the anthers of long styled with smaller pollen-grains contain many more shrivelled & …
- … heterostyled plants, the anthers, like the pollen-grains, were often smaller in the long- …
- … styled flowers, which contain the larger pollen-grains, being longer than those of the …
- … determined that the occurrence of smaller pollen-grains in a long-styled plant was often …
- … sent sketches of Pulmonaria angustifolia pollen from opened flowers, evidently measured …
- … CD gave comparative measurements of the pollen-grains. In CD’s diagram, the dotted line …
To W. E. Darwin 22 June [1866]
Summary
Polymorphism in Rhamnus.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 22 June [1866] |
| Classmark: | DAR 185: 15 |
| Letter no: | DCP-LETT-5131 |
Matches: 6 hits
- … Now the great thing is to be sure that the pollen grains differ in size in the two males. …
- … Sethia, Lythrum, and Oxalis that the pollen grains from the longer stamens in the short …
- … is unfortunately against y r . view. But as the pollen is equal in the two forms of Linum …
- … you are sure about the difference in size in the pollen of the two males, the case must be …
- … William frequently measured the sizes of pollen-grains with the aid of a camera lucida ( …
- … are heterostyled, CD had found that the pollen-grains of the two forms, unlike other …
To W. E. Darwin 30 [June 1866]
Summary
Cuttings have arrived. Different flower forms [in Rhamnus?].
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 30 [June 1866] |
| Classmark: | DAR 185: 17 |
| Letter no: | DCP-LETT-5136 |
Matches: 4 hits
- … show considerable difference in the two pollens, & I now believe in your discovery, which …
- … anthers received this morning contained pollen too shrivelled to measure. — Next summer I …
- … till we have tested power of the two pollens on the two females. — It is just possible …
- … 24 June 1866] ). William had sent drawings of pollen and styles of Rhamnus cathartica with …
To W. E. Darwin [5 May 1863]
Summary
Discusses dimorphic plants.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [5 May 1863] |
| Classmark: | DAR 210.6: 110 |
| Letter no: | DCP-LETT-4140 |
Matches: 4 hits
- … I sh d . anticipate that form (1) would be perfectly fertile with own pollen & the second …
- … form would require pollen from no r I. — Do for Heaven-sake mark the place & get me seed …
- … the compound microscope, I cannot compare pollen; & 2 or 3 flowers would suffice just that …
- … with imperfect anthers destitute of pollen: this second form bears seeds plentifully & …
From H. E. Darwin to W. E. Darwin [18 May 1864]
Summary
CD would like to see Rhamnus, as an American species is dimorphic.
Sends red cowslip pollen to be measured.
| Author: | Henrietta Emma Darwin; Henrietta Emma Litchfield |
| Addressee: | William Erasmus Darwin |
| Date: | [18 May 1864] |
| Classmark: | DAR 210.6: 118 |
| Letter no: | DCP-LETT-4442 |
To W. E. Darwin 5 May [1864]
Summary
Experiment instructions.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 5 May [1864] |
| Classmark: | DAR 185: 13 |
| Letter no: | DCP-LETT-4483 |
Matches: 1 hit
- … another seedling— Soak the common cowslip pollen rather the longest. — I will be merciful …
To W. E. Darwin [31 May 1862]
Summary
Wants WED to forward dried Malaxis to G. C. Oxenden.
Has been dissecting Viola flowers.
[Letter from Emma Darwin to WED, verso p. 3.]
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [31 May 1862] |
| Classmark: | DAR 210.6: 98 |
| Letter no: | DCP-LETT-3580 |
From Henrietta Emma Darwin to W. E. Darwin [16 March 1864]
Summary
CD wants WED to make some measurements on mid-styled [Primula sinensis] plants.
| Author: | Henrietta Emma Darwin; Henrietta Emma Litchfield |
| Addressee: | William Erasmus Darwin |
| Date: | [16 Mar 1864] |
| Classmark: | DAR 210.6: 116 |
| Letter no: | DCP-LETT-3633 |
To W. E. Darwin [24 June 1866]
Summary
Polymorphic flowers of Rhamnus [see Forms of flowers, p. 294].
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [24 June 1866] |
| Classmark: | DAR 185: 16 |
| Letter no: | DCP-LETT-5132 |
To W. E. Darwin [10 May 1863]
Summary
Thanks WED for his botanical specimens and observations.
Discusses Corydalis and the fertilisation of Fumariaceae.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [10 May 1863] |
| Classmark: | DAR 210.6: 111 |
| Letter no: | DCP-LETT-4151 |
To W. E. Darwin [after 14 July 1862]
Summary
Leonard’s illness.
Polymorphism in valerian and Erythraea.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | [after 14 July 1862] |
| Classmark: | DAR 185: 12 |
| Letter no: | DCP-LETT-3650 |
Matches: 1 hit
- … Look to roughness of stigmas & size of pollen-grains in the 2 forms. — I sh d . enjoy …
To W. E. Darwin 7 [July 1869]
Summary
Thanks him for his excellent observations [on Epipactis?]; would like WED to watch for some large insect visiting the plant.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 7 [July 1869] |
| Classmark: | DAR 210.6: 130 |
| Letter no: | DCP-LETT-6819 |
Matches: 1 hit
- … about one point— viz whether the fly with pollen-masses attached to it, crawled out over …
To W. E. Darwin 19 [June 1866]
Summary
Different forms of flowers of Rhamnus.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 19 [June 1866] |
| Classmark: | DAR 185: 14 |
| Letter no: | DCP-LETT-5125 |
Matches: 1 hit
- … flowers had fully formed stamens, but no pollen ( Correspondence vol. 9, letter to Asa …
To W. E. Darwin 22 October [1861]
Summary
Tells of a shooting competition at Down.
Has been working hard at orchid drawings with G. B. Sowerby, Jr.
| Author: | Charles Robert Darwin |
| Addressee: | William Erasmus Darwin |
| Date: | 22 Oct [1861] |
| Classmark: | DAR 210.6: 80 |
| Letter no: | DCP-LETT-3294 |
Matches: 1 hit
- … a splendid Orchis, which shoots out its pollen-masses like an arrow on to insect. — We are …
| letter | (24) |
| Darwin, C. R. | (22) |
| Darwin, Emma | (2) |
| Darwin, H. E. | (2) |
| Litchfield, H. E. | (2) |
| Wedgwood, Emma | (2) |
| Darwin, W. E. | (24) |
| Darwin, C. R. | (22) |
| Darwin, Emma | (2) |
| Darwin, H. E. | (2) |
| Litchfield, H. E. | (2) |
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 …
