Essays upon heredity and kindred biological problems / by August Weismann ; authorized translation edited by Edward B. Poulton, Selmar Schönland and Arthur E. Shipley.

  • August Weismann
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Essays upon heredity and kindred biological problems / by August Weismann ; authorized translation edited by Edward B. Poulton, Selmar Schönland and Arthur E. Shipley. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    strosities which, have arisen from unknown changes in the germ. Similar monstrosities have been known for a long time, and no one has ever doubted that they can be transmitted. It would be equally justifiable to derive the cats with extra toes from an ancestor of which the toes had been trodden upon, as to derive the tailless cats of the Isle of Man from an ancestor of which the tail had been cut off by a cart passing over it, and thus to regard the existence of the race as a proof of the transmission of mutilations. But even if it were certain that the tail of the mother cat had been mutilated, such a fact would not necessarily prove that the rudimentary tails of the offspring were due to transmission from the mother : they might have been transmitted from the unknown father. This is probably not the case with Dr. Zacharias' cat, for tailless kittens occurred in several families produced by the same mother; but in other cases the possibility of the possession of innate taiUessness by the father must be taken into account. The following case is, in this respect, very instructive. Last «immer, my friend. Prof. Schottelius, of Freiburg, brought me a kitten with an innate radimentary tail, which he had accidentally discovered as one of a family of kittens at Waldkirch, a small town in the southern part of the Black Forest. The mother of the kitten possessed a perfectly normal tail; the father could not be identified. A closer investigation resulted in the following rather un- expected discovery. For some years past, tailless kittens have frequently appeared in the families of many different mother cats at Waldkirch, and this fact is explained in the following manner. are given. Additional generations and many more families have been since observed, and an account of tbese observations will shortly be published in the same paper. The breed originally came from Bristol. In the observations recorded, the ab- normality of the offspring is an indication of the hereditary strength of the female parents, while the degree of normality is a similar test of heredity through the male parents; for the female parents were always abnormal, the male parents always normal. The most abnormal kitten observed possessed seven toes on each forefoot, seven toes on the right hind foot (three more than the normal number), and six on the left hind foot. Kittens with seven toes on the forefeet and six on the hind were comparatively common, and all intermediate conditions between this and the normal were of frequent occurrence. Cats with extra toes are, I think, not uncom- mon in most countries, and the fact that the peculiarity is transmitted is also well known. The object of the investigation alluded to was to observe the transmission systematically through many generations.—E. B. P.]