TOSA. FOWL AND WHITE COCHIN. 



47 



other (No. 7, " General Oyatna ") did not have its tail stroked. The two 

 birds were treated similarly, except that Admiral Togo was confined to his 

 perch during all but about two to six hours per day, while General Oyama 

 had free run with the hens. The experiment was begun July 20, 1904, 

 when the cocks were 103 days old, and was continued until March, 1905, 

 when " Oyama " died of roup. 



The relative growth of the corresponding feathers of the two males is 

 shown in a series of curves (text figure D). The full line is the curve of 



FIG. D. Curves of growth of certain tail feathers of Togo (No. 3, full line) and Oyama (No. 7, dotted 

 line). MI, first right middle tail feather; M s , M'j, second right and left middle tail feathers; M, 

 third right tail feather ; S, right sickle. 



the stroked feather ; the dotted line that of the unstroked. These curves 

 show several things. 



First, the average rate of growth of one of the tail feathers in the Tosa 

 fowl is about 3 mm. per day, or an inch a week. Consequently, if growth 

 is uninterrupted and the feather does not break, it should come to be over a 

 meter long by the end of one year. The extremely long feathers 5 meters 

 or more on record are acquired by (a) rapid growth, (3) continuous growth, 

 O) preservation of the tail from breakage, and (d) long life of the individual. 

 If stroking has any effect it must be by altering one or more of these elements. 



Second, the curves show fluctuations in the rate of growth due to fluctua- 

 tions in the condition of the fowl. 



Third, in the case of those feathers that were studied during the greatest 



