128 THE STORY OF A BIRD LOVER 



ney-swift of North America could not have bred 

 in chimneys, for probably there were none. The 

 fact that the civilization and settlement of a new 

 country can so radically affect all the representa- 

 tives of a given kind of bird as to change its 

 breeding habits, at least so far as its disposition of 

 the nest is concerned, is suggestive. 



An agreeable recollection of the brief stay we 

 made at Colorado Springs is a pleasant acquaint- 

 ance formed with Mr. and Mrs. Jackson, which 

 added a new interest, if that were needed, to the 

 graphic and picturesque descriptions of the West 

 and Western life, which Mrs. Jackson, as " H. H." 

 gave to the world. 



Presently we were again crossing the plains; 

 and in a little time the pleasures of the summer 

 were retrospects, while the tangible results of the 

 work accomplished on this expedition were appar- 

 ent in the additions (some seven hundred birds in 

 all) to the collections of the growing museum. 



During the succeeding university year, that- of 

 1878 and 1879, my work kept me in Princeton. 

 It was the regular, routine kind, consisting of 

 my duties as curator of the museum, instruc- 

 tion to special students, of whom I had several this 

 year, and a course of lectures and laboratory work 

 on comparative anatomy of vertebrate animals. 



It is my purpose to discuss briefly at this point 

 some of the conditions that existed in the bird 



