33 THE ZOOLOGIST. 



and Asia it seldom breeds below the arctic circle, except at high 

 elevations : Archangel seems to be too far south to suit its 

 requirements ; but curiously enough, on the shores of the Sea of 

 Ochotsk, Middendorfi" found it breeding as far south as lat. 55°. 



The Whimbrel, Numenius fhceopus, is also an exclusively 

 arctic species during the breeding season, Iceland and the 

 islands between it and Scotland (where it also breeds in the 

 most northerly counties), and probably Kamtschatka, being the 

 only localities south of the arctic circle which it frequents in 

 summer. 



The Greenshank, Totanus glottis, is another arctic species, 

 though it does not breed so far north as the other birds above 

 named. In Scotland it breeds much farther south than on any 

 part of the Continent, a statement which probably applies to 

 many other species. 



If time and space permitted it would be interesting to 

 compare the breeding range in the British Islands of many 

 other arctic or subarctic birds with their breeding range on 

 the Continent. The Great Skua, Stercorarius catarrhactes, 

 Eichardson's Skua, S. richardsoni, the Black-throated Diver, 

 Colymhus arcticus, the Fulmar Petrel, Fulmarus glacialis, and 

 several species of Ducks, all come under the category of 

 arctic birds which breed at exceptionally low latitudes in 

 Scotland. 



Now it is a remarkable fact that not one of these birds 

 breeds either in England or Ireland ; and the only conclusion 

 that we can arrive at is that, from an ornithological point of 

 view, Scotland belongs to the Arctic Eegions ! But like most 

 other remarkable facts it admits of an easy explanation. 



This explanation is climatic. Most, if not all, of the species 

 named breed in July. A reference to a map on which the 

 isothermal lines for July are traced will be found to explain all 

 these apparent anomalies in a most remarkable manner. In 

 Keith Johnston's 'Physical Atlas' there is a map of the world 

 in which the mean temperature for the month of July is given 

 in various parts of the earth. 



Pioughly speaking, the birds under consideration draw the 

 line a few degrees below 60° Fahrenheit. For some special 

 reason they do not breed in any locality where the mean tem- 

 perature for the month of July is as high as 60°, their reason 



