73 



is, however, still comparatively scarce and dear, most 

 aviary-bred birds being typical. When the yellow 

 form is crossed with the type the latter is dominant : 

 intermediate forms apparently do not occur. A blue 

 form has been bred on two occasions from yellow birds. 

 The sexes of Budgerigars are always easy to dis- 

 tinguish in adult birds, the cock having a rich blue 

 cere, and the hen a pale blue or brown one. They 

 breed freely in aviaries, needing only a cocoa-nut 

 husk or a box with a hole in it to nest in. Several 

 pairs do better than one, but odd birds should be 

 avoided. As many as half-a-dozen young may occur 

 in a brood, and several broods may be reared in a 

 season. They are easily fed, needing only millet, 

 canary-seed, oats, and tufts of grass, although some 

 soaked bread, squeezed dry, is of use when young are 

 being reared. So easy is their propagation that many 

 are bred for profit. Even adult males will often dis- 

 play great aptitude at imitating the songs of other 

 birds, and hand-reared ones can be taught to talk. 

 The Budgerigar is peculiarly suitable for Mendelian 

 experiments, owing to its few and definite variations. 

 Selection might be attempted with a view to improving 

 the bird's imitative powers, and would be profitable if 

 successful. If the blue form occurred, its cultivation 

 would pay well, as even that of the yellow form does. 

 The price of typical Budgerigars varies, accord- 

 ing to season, from 4s. 6d. to about los. 6d. per pair; 

 the yellow form costs from i6s. per pair upwards. 



The CoCKATiEiv or Cockatoo Pakrakeet {Cal- 

 opsittactts 7iov(Z - hollaiidicB) is an elegantly - sli aped 

 crested grey bird about the size of a missel-thrusli, 

 with a white patch on the wing and an orange spot 

 on the cheeks. Tlie male has the head yellow and 

 lateral tail feathers black, while in the female there is 

 hardly any yellow on the head and the lateral tail 

 feathers are barred yellow and black. 



