YOSHIMARO TAN AK A 227 
later than the 3-moulters. The following diagram may illustrate more clearly 
the differential development of the two strains. 
V STAGE IV STAGE III STAGE II STAGE I STAGE 
mounting IV moult III moult II moult I moult 
— ! ^ ! ! i 4-moulter 
j* \a 
I 1 I S-movlter 
mtunt'ng III moult II moult I moult 
IV STAGE III STAGE II STAGE I STAGE 
Text-fig. 9. 
Owing to its great variability, the body size or weight can not be taken 
as the criterion for distinguishing 3-moulters from 4-moulters. The size of 
the head-case, on the other hand, does not show any marked increase during 
the same stage ; and further the individual variation is less extensive as com- 
pared to the body size. The head-case grows at every moult, and in a full- 
grown 4-moulter (fifth stage) the head is larger than in a full-grown 3-moulter 
(fourth stage), though the head-size of 3-moulter exceeds that of a 4-moulter 
of the corresponding stage (e. g. fourth or third). Taking the a period in the 
diagram, for instance, the large-headed 3-moulters are not difficult to dis- 
tinguish from the small-headed 4-moulters. On the contrary, taking the b 
period in the figure, the relative size of the head in the two strains is just the 
reverse. I mention this because the distinguishing criterion is so important 
for avoiding errors that may otherwise vitiate the results of experiments. 
There were in my experiments, only a few cases which rendered the distinction 
uncertain on account of considerable fluctuation in the head size. 
The moulting character is constant to some extent ; I have in my pos- 
session several strains which bred true in regard to this character for gener- 
ations. Moreover, the character is Mendelian, 3-moulting dominating over 
4-moulting. The cases of simple Mendelian inheritance are shown below. 
Chinese 3-moulters (f'Sze-chuan" race) were crossed with Japanese 4- 
moulters (pale-quail strain); F 2 generation consisted of 3-moulters only. The 
Fj individuals were mated inter se, as well as cross-bred with the recessives 
with following results. 
