CHAPTER IV. 



RUMPLESSNESS. 



The tail of vertebrates is, historically, the post-anal part of the trunk. 

 Containing no longer any part of the alimentary canal, it has lost much of 

 its primitive importance, so that its disappearance in any case is a matter 

 of relatively httle importance. Accordingly we find groups of animals in 

 which it is rudimentary or wholly absent, such as many amphibia and the 

 anthropoid apes and man. In all recent birds the tail is a distinct but much 

 reduced organ — the uropygium — which contains several vertebrae in a 

 degenerate condition. The uropygium supports the tail feathers, which 

 are of much use in directing the bird in flight, but in ground birds, such 

 as the grouse and poultry, seem to function only for display in the male 

 and, in the female, to facilitate copulation. 



Now, among various typically tailed vertebrates the tail is sometimes 

 absent. Tailless dogs, cats, sheep, and horses are known; on the other 

 hand, several cases of tails in man have been described (Harrison, 1901). 

 Thus the tail is a part of the body subject to sporting; and it has also become 

 the differential character for some specific groups. In other words, it is an 

 organ that has played an important part in evolution and consequently 

 its method of inheritance is a matter of great interest. 



The origin of the taiUess poultry which I have bred has been twofold. 

 The most important strain is that referred to in an earUer report* as 

 Bantam Games. The second lot consists of rumpless fowl that have arisen 

 in my yards, spontaneously, from normal blood. Of these more later. 



The two rumpless Game cocks bore the numbers 117 and 116. Dr. A. G. 

 Phelps, of Glens Falls, New York, from whom the birds were purchased, 

 wrote that he had imported No. 117 from England, and No. 116 was its 

 son. The birds were very closely similar in all external features. 



The matings made with No. 117 and their results are given in table 26. 



Table 26. — Progeny of tailless cock and tailed hens. 



* Davenport, 1906, pages 62 to 64, fig. 46. 



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