HYBRIDISM AMONG COCKATOOS. 15 



they are mostly sterile. The present case is no exception; 

 the characters of C. galerita and L. nasica have very 

 obviously blended, and the resulting hybrid stands between 

 the two species, but somewhat nearer to Cacatua than to 

 L i c m e t i s . 



A simple Mendelian relation would have been shown if, for 

 example, the sulphur-yellow of the Cacatua had been 

 dominant and the red of Licmetis recessive, and on subse- 

 quent crossing of the hybrid (assuming that it was possible) 

 if 75 per cent, of the offspring had been entirely yellow and 

 25 per cent, entirely red. But in the present case of hybridism 

 we do not find any definite evidence of the existence of such 

 dominance in any of the characters examined. It is true that 

 the colour of the hybrid is nearer to yellow than to red, and 

 that in this character there is prepotency on the part of the 

 male-bird; but the yellow colour of the hybrid is not the 

 sulphur-yellow of Cacatua; the latter colour has become 

 blended with red to form an orange crest, orange lores, and a 

 beautiful gold under-plumage to the head and neck. 



Again, it would not serve any useful purpose to regard the 

 possession of a crest as a dominant character. The short, 

 straight, orange crest of the hybrid is obviously a kind of 

 mean between the long recurved sulphur-yellow crest of 

 Cacatua and the short, white and red feathers of the crown 

 of Licmetis. 



A similar blending of characters is seen in the position of 

 the nostrils, the condition of the cere with reference to the 

 feathering, the colour and shape of the upper and lower 

 mandibles, and the shape of the forehead. 



The characters which do not readily admit of numerical 

 expression are grouped together in the accompanying table 

 (p. 16)._ 



It will be noticed that under " Hybrid " more of the 

 characters are found in the column "nearer Cacatua" than 

 elsewhere, but it must be remembered that in every case the 

 influence of Licmetis is very distinctly obvious, and, except 

 perhaps in the character of the possession or non-possession 



