HYBRIDISM AMONG COCKATOOS. 23 



From this point of view a glance at Table III may be of 

 interest. In this table the characters of the different species 

 of Cacatua, as given in the British Museum Catalogue, are 

 rather imperfectly summarised; but we are able to see the 

 general range of variability in the genus, with a view to 

 obtain some insight into the hereditary tendencies of the 

 male-parent ; and also of the female-pai'ent, since the genus 

 Lie metis to which the latter belongs is closely related to 

 C a c a t u a . 



For example, the general coloration in the different species 

 of Cacatua is nearly always white, and we find as the result of 

 the blended inheritance that the amount of coloration in the 

 hybrid is less than half of that of the female-parent. 



The recurved condition of the crest is found in less than 

 half of the species of Cacatua, and we notice that the 

 recurved feathers of the male-parent are not so strongly 

 impressed on the offspring as to counteract the influence of 

 the female-parent. Yellow or white crests occur in the 

 majority of the species of Cacatua, and the amount of red 

 coloration mixed with the yellow of the hybrid is compara- 

 tively small. 



The feathered and non-feathered conditions of the cere are 

 about equally divided in the different species, and in the 

 hybrid the condition with respect to this matter is almost 

 exactly intermediate between the two parents. 



The bill is more often black than light-coloured in the 

 various species, and in the hybrid it is much nearer to black 

 than white. 



In nearly all of the species of Cacatua the naked skin 

 around the eye is oval or circular, and in the hybrid it is 

 roughly circular. The shade of colour of the naked skin, 

 whether Avhite, blue or grey, varies considerably in the 

 different species of Cacatua, and the hybrid in this character 

 is closely intermediate between the two parents, thus indicat- 

 ing that there is no marked preponderating influence in either 

 direction. 



The general shape of the upper and lower mandibles is very 



