42 IN THE HEMLOCKS. 



they are as unconscious of Spaulding as Spaulding is 

 of them. 



Walking the other day in an old hemlock wood, I 

 counted over forty varieties of these summer visitants, 

 many of them common to other woods in the vicinity, 

 but quite a number peculiar to these ancient solitudes, 

 and not a few that are rare in any locality. It is quite 

 unusual to find so large a number abiding in one for- 

 est, — and that not a large one, — most of them nest- 

 ing and spending the summer there. Many of those 

 I observed commonly pass this season much farther 

 north. But the geographical distribution of birds is 

 rather a climatical one. The same temperature, though 

 under different parallels, usually attracts the same 

 birds ; difference in altitude being equivalent to the 

 difference in latitude. A given height above the sea 

 level under the parallel of thirty degrees may have the 

 same climate as places under that of thirty-five degrees, 

 and similar Flora and Fauna. At the head-waters of 

 the Delaware, where I write, the latitude is that of 

 Boston, but the region has a much greater elevation, 

 and hence a climate that compares better with the 

 northern part of the State and of New England. Half 

 a da> -: s drive to the southeast brings me down into 

 quite a different temperature, with an older geological 

 formation, different forest timber, and different birds; 

 — even with different mammals. Neither the little gray 

 rabbit nor the little gray fox is found in my locality, 

 but the great northern hare and the red fox. In the 



