NATURAL HISTORY OF SELBORNE 119 



this death-like stupor as a defect of heat. And farther, it is 

 reasonable to suppose that two whole species, or at least 

 many individuals of those two species of British hirundines 

 do never leave this island at all, but partake of the same 

 benumbed state ; for we cannot suppose, that after a 

 month's absence, house-martins can return from southern 

 regions to appear for one morning in November?- or that 

 house-swallows should leave the districts of Africa to enjoy 

 in March the transient summer of a couple of days. 



I am, &c. 



1 The Martins which appear at the end of March are early arrivals, whose 

 progress northwards is arrested by a cold " snap," such as often occurs in England 

 in spring. Those which appear in November are doubtless belated young birds 

 from the later broods. See foot-notes to vol. i. pp. 36, 48, 102. It still remains a 

 remarkable fact that the true winter home of the House-Martin remains undis- 

 covered. The species did not appear in Lord Delamere's recent collection from 

 the Athi River in British East Africa, though a number of- our summer migrants 

 were procured by him in that region. [R. B. S.] 



