62 The Wilson Bulletin — No. 51. 



been made oi the need for more extensive and more exact 

 knowledge of the breeding habits of the birds. The nest 

 location, nest material (of what sort and where obtained), 

 how the nest is made, by both or only one parent; the possi- 

 bility that two pairs of birds unite in one nest, particularly 

 among the more gregarious species; the relation of the nest 

 constructii n to season and weather; the time in building; the 

 real office it performs in the act of breeding for parents, eggs 

 and young. 



There is a whole chapter in the " story of the birds " in the 

 eggs. Who will write that chapter? Some of us may be 

 strongly inclined to the oological side of bird study. If so 

 here is a nearly untrodden field. It is for you. if you fee! 

 this tendency, to bring' forward a new oology. 



A little aside from the subject of oology proper is the em- 

 bryology of nearly all of our native birds. The concern here 

 is rather with the late than with the earlier stages of incu- 

 bation. At what time do the first suggestions of the future 

 feathers appears as little papillae on the skin surface ? The 5th 

 day of incubation will probably be found the earliest date, 

 lb w rapidly do these papillae grow? What is their condition 

 at hatching? When do the true feathers begin to appear be- 

 neath the skin and at the lower end of the down? How are 

 thtse feathers arranged on the body? What is their rate of 

 growth ? How does their rate of growth correspond to the 

 growth of the voting bird? Why is down first followed by 

 feathers? What is the relation of the color pattern of the nest- 

 ling or downy young to the nest and other environment ? 

 What is the relation of the color pattern of the downy young 

 to the first feather plumage, and of the first feather plumage 

 to succeeding ones? Just here lies the secret to the develop- 

 ment of the color patterns because we have given almost no 

 attention to the downy young and to the earliest stages of the 

 first feather plumage. It is a very enticing field for the orig- 

 inal worker. 



Coming to the adult birds, we don't begin to know yet all 

 about their geographical distribution and migrations. The 

 winter distribution and the spring migrations are compara- 

 tivelv easv and fairlv well known, because at these times peo- 



