RUMPLESSNESS. 



39 



of fact recorded chiefly in chicks that failed to hatch, but it was occasionally 

 noticed in older birds, being then usually associated with a slight convexity 

 of the back. In some of the families the uropygium is recorded as small 

 in suspiciously close to 25 per cent of the offspring. There is Uttle doubt 

 in my mind that this small uropygium represents in some way the " absence" 

 of tail that was expected. 



The next step was to cross the other rumpless bantam (No. 116), to 

 see if he behaved hke his father. Accordingly, in pen 653, I replaced the 

 cock No. 117 by 116, the hens remaining the same, and got the result shown 

 in table 29. 



Table 29. Heterozygous mated with No. JIG. 



Here we get a result almost exactly in accord with Mendelian expecta- 

 tion. Having, now, obtained rumpless hens, it became possible for the 

 first time to test the inheritance of rumplessness in both parents. The 

 result is shown in the table 30. 



* Both from chicks that died in shell. t From a hatched chicken. 



Table 30 is unfortunately small; one may say, fragmentary. Rump- 

 less hens are incapable of copulating unless the tail coverts are trimmed; 

 moreover my birds have been so much inbred that they are very weak; 

 finally, the chicks are so small that it is impracticable to rear them in brood- 

 ers and the eggs are particularly apt to be broken by the brooding hens. 

 However, it suffices to show that two tailless fowl are able to throw some 

 tailed offspring. 



