The foundations of The origin of species : a sketch written in 1842 / edited by Francis Darwin.
- Charles Darwin
- Date:
- 1909
Licence: Public Domain Mark
Credit: The foundations of The origin of species : a sketch written in 1842 / edited by Francis Darwin. Source: Wellcome Collection.
75/94 page 43
![species now become ill-suited to its habitat, or rather with a better place opened to it in the economy of Nature. It would not matter to the full-grown cat whether in its young state it was more or less eminently feline, so that it become so when full- grown. No doubt most variation, (not depending on habits of life of individual) depends on early change1 and we must suspect that at whatever time of life the alteration of foetus is effected, it tends to appear at same period. When we (see) a ten¬ dency to particular disease in old age transmitted by the male, we know some effect is produced during conception, on the simple cell of ovule, which will not produce its effect till half a century afterwards and that effect is not visible2. So we see in grey-hound, bull-dog, in race-horse and cart¬ horse, which have been selected for their form in full-life, there is much less (?) difference in the few first days after birth3, than when full-grown: so in cattle, we see it clearly in cases of cattle, which differ obviously in shape and length of horns. If man were during 10,000 years to be able to select, far more diverse animals from horse or cow, I should expect there would be far less differences in the very young and foetal state: and this, I think, throws light on above marvellous fact. In larvae, which have long life selection, perhaps, does much,—in the pupa not so much4. There is no 1 See the discussion to this effect in the Origin, Ed. i. pp. 443-4, vi. p. 610. The author there makes the distinction between a cause affecting the germ-cell and the reaction occurring at a late period of life. 2 Possibly the sentence was meant to end “ is not visible till then.” 3 See Origin, Ed. i. pp. 444-5, vi. p. 611. The query appended to much less is justified, since measurement was necessary to prove that the grey¬ hound and bulldog puppies had not nearly acquired “ their full amount of proportional difference.” 4 (The following discussion, from the back of the page, is in large measure the same as the text.) I think light can be thrown on these facts. From the following peculiarities being hereditary, [we knowr that some change in the germinal vesicle is effected, which will only betray itself years after] diseases —man, goitre, gout, baldness, fatness, size, [longevity (illegible) time of](https://iiif.wellcomecollection.org/image/b31351761_0077.jp2/full/800%2C/0/default.jpg)
