356 



STERNUM OF THE JACKO PARROT. 



between them, where they seek it. The sternum is of 

 course modified to suit these differences ; and thus 

 no one bird can in that respect be considered as 

 typical of the whole order. That of the woodpecker, 

 which we have given, may be perhaps considered as 

 the one extreme, while the following, which is half 

 the lineal dimensions of nature, may be regarded as 

 the other. 



Jacko Parrot. 



The posterior part of this sternum bears some 

 resemblance to that of the diurnal birds of prey, but 

 the anterior portion and the attached bones are very 

 different. Its relative length is also nearly the same. 

 But all this similarity of the hinder parts of the two 

 sterna merely shows, that parrots and diurnal birds 

 of prey have both a very powerful and firm action in 

 those muscles wliich move their tarsi or toes, while 

 the different actions depend on the structure of the 

 toes themselves. It is, however, of no inconsiderable 

 importance in facilitating our knowledge of the rela- 



