XI PHENOMENA OF ORGANIC NATURE 415 



and at the base of the beak, may vary enormously ; 

 so may the length of the eyelids, the shape of the 

 nostrils, and the length of the neck. I have al- 

 ready noticed the habit of blowing out the gullet, 

 so remarkable in the Pouter, and comparatively so 

 in the others. There are great differences, top, in 

 the size of the female and the male, the shape of 

 the body, the number and width of the processes 

 of the ribs, the development of the ribs, and the 

 size, shape, and development of the breastbone. 

 We may notice, too and I mention the fact be- 

 cause it has been disputed by what is assumed to 

 be high authority, the variation in the number 

 of the sacral vertebra. The number of these 

 varies from eleven to fourteen, and that without 

 any diminution in the number of the vertebrae of 

 the back or of the tail. Then the number and 

 position of the tail-feathers may vary enormously, 

 and so may the number of the primary and second- 

 ary feathers of the wings. Again, the length of 

 the feet and of the beak, although they have no 

 relation to each other, yet appear to go together, 

 that is, you have a long beak wherever you have 

 long feet. There are differences also in the 

 periods of the acquirement of the perfect plum- 

 age the size and shape of the eggs the nature 

 of flight, and the powers of flight so-called 

 " homing " birds having enormous flying powers ; 1 



1 The "Carrier," I learn from Mr. Tegetmeier, does not 

 carry ; a high-bred bird of this breed being but a poor flier. 



