CHAPTER V. 



^A/INGLESSNESS. 



The entire absence of appendages is a rare monstrosity, few cases hav- 

 ing been cited even for man. In my experience with poultry, out of about 

 14,000 birds I have obtained one that had no wing on one side of the body, 

 but this unfortunately died before being bred from. A second bird was 

 given to me by a fancier. The bird was an Indian Game, a vigorous cock, 

 which was handicapped by his abnormality in two ways. First, whenever 

 he fell upon his side or back he was unable to get upon his feet without aid. 

 On several occasions he evidently had spent hours upon the ground before 

 he was discovered and picked up. The wings are thus clearly most impor- 

 tant to the fowl in enabling it to regain its feet after having become prone. 

 Secondly, he was unable to tread a hen, since this act requires the use of 

 wings as balancers. He was, however, able to copulate with small birds 

 without leaving the ground. Thus in two respects his abnormality would 

 have proved fatal in nature. First, because of the personal risk, the greater 

 since a prone bird must fall an easy prey to predaceous enemies; and 

 secondly, because of the risk to his germ-plasm. Little wonder, then, that 

 this abnormaUty should not be known among wild ground-birds. 



Mated to 6 hens this wingless cock produced 130 chicks in 1907, of 

 which all had two wings. The following year he was mated to his daughters, 

 but died without leaving offspring. So I used a son of his to mate with his 

 own sisters and half-sisters. The progeny in this F^ generation consisted 

 of 223 chicks, all of which had two wings. Thus, no trace of winglessness 

 appeared in any of the descendants of the wingless cock. 



The explanation of this case is not very certain, in view of the limited 

 data. It seems to resemble the behavior of No. 117, the rumpless cock. 

 And following the interpretation given in his case I would conclude that 

 winglessness is dominant to the normal condition, that the original wingless 

 cock was a heterozygote, and that the dominance of winglessness was 

 imperfect in the first generation. On this hypothesis his son may well 

 have been a pure recessive, and then all of his descendants, in turn, would 

 be either recessives or heterozygotes (with imperfect dominance). It is, 

 on the other hand, possible that the wingless cock was a pure dominant, 

 but that the potency of the inhibitor was so sUght as not to appear in the 

 heterozygotes or even in extracted dominants. 



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