62 The Wilson Bulletin — No. 67. 



Ontario shore through the shoal north of them. Whatever 

 the facts may be it seems clear that at no very ancient date 

 the land masses were much more extejisive and much nearer 

 together, and the expanse of water over which the birds must 

 pass to and from the north much less than at present. 



I have, selected Pelee, Middle, and Kelley's Islands for 

 brief descriptions because they seem to form the most im- 

 portant highway of migration, and because they represent the 

 types of islands forming this archipelago except the gravel 

 islands of Big and Little Chicken, where the Common Terns' 

 nest in great numbers. These small islands are limestone 

 ridges covered with gravel. Big Chicken is an angular island 

 of perhaps two acres fextent, with one willow tree (there has 

 been another tree which recently blew down), a mass of gourd 

 vines in the summer, and a small fish house. Little Chicken 

 is a narrow ridge of limestone rock, with outlying ledges of 

 considerable extent on all sides nearly reaching the surface 

 and hence protecting this narrow ridge from storm waves. 

 There are several small willow trees and bushes along the 

 north border, and a dense growth of 'smartweed' each side of 

 the gravel ridge which occupies its center. About a rod in 

 wndth and fully ten rods in length of this island lies above 

 summer storm waves. Terns' nests are placed as thickly all 

 over this area as it is possible for the birds to sit without 

 serious quarreling. 



Put-in-I)ay is like Kelley's , but larger and with more woods 

 and fields. It rises to about 69 feet above the lake level at the 

 hotel. Middle Bass is only 11 feet above the lake level, with 

 few trees, but extensive vineyards, and a small pond where 

 King Rails' nests are numerous. North Bass rises twenty- 

 four feet. It has considerable woods and relatively few fields. 

 The related small islands do not present any unusual features. 



While North Harbor Island belongs to the type of larger 

 islands it presents some interesting features. It is a limestone 

 ridge trending nearly due north and south, not above ten rods 

 wide by three times that length, covered by a dense growth 

 of deciduous trees, most numerous among which is the hack- 



