24 ERNEST WAKEEN. 



similar in all the species of C a c a t u a , while it is rather peculiar 

 in Licmetis; in the hybrid the general shape is nearer to 

 that in the former genus than to that in the latter. 



Lores separable from the surrounding plumage in colour are 

 seen apparently in only three or four of the fifteen species of 

 Cacatua, and to be comparable with the above results the 

 colouring of the lores in the hybrid should be less than half 

 the amount seen in Licmetis. The amount of colouring in 

 the hybrid is certainly considerably less than in the female- 

 bird, but it is greater than one-half, and consequently in this 

 character there is some prepotency on the part of the mother. 



With reference to the absolute dimensions of general body- 

 length, length of tail and bill, given in the second, third and 

 fourth columns of Table III, it will be seen that there is great 

 variation in the different species, and this is also the case with 

 the relative lengths of the tail and bill. Consequently we 

 perhaps should not expect to find any very strong prepotent 

 action. As a matter of fact, the absolute dimensions in the 

 hybrid are not so very far removed from the means of the 

 dimensions of the male- and female-parent. The means for 

 the parents of the three dimensions are 15"5, 6'4 and 1*74 

 inches respectively, and the measurements in the hybrid are 

 15'0, 7"0 and 1"7 inches respectively; the male-parent is 

 prepotent with reference to the length of tail and beak, and 

 the female-parent with respect to body-length. The mean 



,. length of tail n ^^ .^ ■ • no £ 1 



ratio ■—- — -^ for all the species is '28, tor male 



length of body 



Cacatua "45, for female Licmetis "36, and for hybrid '45. 



Thus, in this case the prepotency of the male-bird has been 



strong enough to counteract the more typical proportion of 



the tail-length seen in the female-bird. 



On the whole it perhaps may be said that old-established 



characters appearing in the majority of the species of a genus 



may from this very fact be regarded as strongly inheritable 



characters, which if present in one parent would tend to be 



impressed on the hybrid to the partial exclusion of any more 



peculiar characters that happened to be present in the other 



