io Gbe Marbler 



favorable to their environment. Under this theory one might hope to find 

 a development of a substitute for a snow shoe on a non-migratory bird whose 

 habits keep it largely upon the ground, while no such development would 

 be expected on a bird that leaves us in the winter for warmer climes. 



This is the only instance that I know of where an animal of any kind 

 grows a special arrangement in the fall for walking on snow. 



The rabbit has a foot well adapted to this purpose, but it is the same, 

 winter and summer. Most animals put on a better skin protection for win- 

 ter, and some change color, being whiter in winter than summer, but the 

 Grouse alone, so far as I know, puts on snow shoes in the fall and takes them 

 off in the spring. 



AMERICAN goldfinch. {Astragalinus tristis.) 



But few of our native birds change the color of their plumage as an 

 adaptation to the season, but our pretty Thistle Bird, or American Goldfinch, 

 undergoes a radical change. In summer he has a bright yellow body with 

 black markings and a black head, while in winter his plumage is all pale 

 brown or sparrow color, and we often fail to recognize in our sombre winter 

 residents the brilliant Goldfinch of our summer. These little birds are gre- 

 garious in the winter and as they fly in small flocks into the trees by the road- 

 side they are frequently mistaken for Sparrows, and in fact are usually called 

 Tree Sparrows. 



There are few things connected with the study of natural history more 

 interesting than the tendency in animals to develop conditions suitable to 

 their environments, and it is surprising to see for how long a time an acquir- 

 ed habit will sometimes survive after its usefulness has ceased. You have all 

 noticed that a dog turns around several times before laying down. Natural- 

 ists tell us that this is a survival of the practice of his forefathers to prepare 

 a bed for themselves in the tall grass ; and since the dog was one of the first 

 animals domesticated by man, this must be a survival from a time counted 

 by centuries. Other habits must have been surrendered and new ones ac- 

 quired, in a comparatively short time. 



chimney SWIFT. [Chaetura pelagica.) 



The common Chimney Swallows always build their nests in chimneys 

 that are unused during their breeding season. They make a semicircular 

 nest of sticks which they glue to the inside wall of the chimney with a se- 

 cretion from their mouths. It is interesting to see the Swallows gather the 

 sticks for their nests, for they do not alight on the ground, but while flying 

 break off dead twigs from trees without stopping in their flight. 



This habit of building in chimneys must have been acquired in a com- 

 paratively short time, for there were no chimneys in this country before the 

 arrival of the white man, and for a long time afterwards the settler had but 



