48 INHERITANCE IN POULTRY. 



period, viz, M 1( M 2 , M' 3 , the stroked feather grew more rapidly than the 

 corresponding unstroked. 



Fourth, the unstroked feathers of No. 7 ceased growing earlier than the 

 corresponding stroked feathers of No. 3. 



Whether the third and fourth items are due to differences in treatment 

 or to other peculiarities of the fowl can not be asserted definitely. In any 

 case the feathers all eventually, at about six months, ceased to grow. 

 Owing to the death of No. 7 soon after, the comparison had to be abandoned. 

 The result agrees with Cunningham's in that stroking prolongs the period 

 of growth ; but the result, depending on three feathers, can hardly be 

 generalized. It would not be surprising, in view of what we know of 

 functional hypertrophy, if it were some day demonstrated that stroking 

 always prolongs the growing period of a feather. This is, however, an 

 entirely different matter from proving that the origin of the long-tailed con- 

 dition of the Tosa fowl was due to, and its maintenance in some way depends 

 upon, stroking. 



A few further cxpenuients have been made with Admiral Togo (fig. 31). 

 I have found, in confirmation of Cunningham, that if a feather that has 

 ceased to grow be forcibly removed it is quickly replaced by another that 

 continues to grow. Thus a feather pulled out January i, 1905, had grown 

 steadily to November i ; but as the bird was needed for breeding and could 

 not be confined, the tail has repeatedly broken off. In September, 1905, it 

 measured over 900 mm. 



As a further criterion of the value of manipulation in causing this great 

 growth of the tail feathers of the Tosa fowl, it becomes important to see 

 how this physiological characteristic is inherited when crossed with a short- 

 tailed individual. This consideration led to the present series of experiments. 



The tail of the Cochin fowl is the shortest of all races of poultry. Thus 

 Wright (1902, p. 245) expresses the ideal of the fancier : " The tail of the 

 cock should be as ahort as possible. ' ' 



3. FOOT FEATHERING. While the Cochin is very heavily feathered on the 

 foot, the Tosa fowl is typically clean-legged. However, No. 3, which is 

 not the father of any of my hybrids, shows a few bunches of rudimentary 

 feathers or hairs on the tarsus. 



4. FOOT COLOR. The willow foot of the Tosa fowl is derived directly 

 from the Jungle fowl. The white foot of the White Cochin seems to be an 

 albinic form of the yellow foot derived from its Indian-Malay ancestry. 



MATERIAL. 



FIRST GENERATION. The mother was a White Cochin Bantam, No. 350 

 (fig. 32), of unknown origin, but apparently pure in respect to the four 

 characteristics here under consideration. The father was imported from 

 Japan, having been purchased in New York city, January, 1904. It has a 

 dark Game coloration (fig. 29). 



