376 Mr. J. Blackwairs Ornithological Notes. 



over, all the British Hirundinidce moult in the interval which 

 elapses between the times of their disappearance and reappear- 

 ance in this country. Such also is the case with the cuckoo and 

 some other species of periodical summer-birds : how utterly irre- 

 concilable this plain fact is with the hypothesis of their passing 

 that interval in a state of torpidity needs scarcely to be insisted 

 upon ; indeed it is absolutely inconceivable that birds in a lethargy 

 so profound as that in which the animal functions seem to be sus- 

 pended should undergo a change of plumage, when Mrs. War- 

 ner's cuckoo, enjoying all the advantages of exuberant animation, 

 high temperature and stimulating nutriment, failed to do so. 



I. now revert to the experiments. Three young house martins, 

 Hirundines urbiccB, were taken from a nest in the chapelry of 

 Blakeley, near Manchester, in September 1827, and were kept 

 in a room without fire. Erom the 21st of the November follow- 

 ing to the 27th inclusive there was a continuance of inclement 

 weather, the maximum temperature for the period being 47°' 5, 

 the minimum 19°, and the mean 33°'39, yet not the least dis- 

 position to become torpid was apparent in the young martins, 

 though they did not long survive the test to which they had 

 been subjected; indeed, for periodical birds to suffer severely, 

 and even to perish from cold and hunger during their sojourn in 

 this country, is no uncommon case ; but a lowering temperature 

 and a decreasing supply of food, when they pass certain limits, 

 are the very conditions which should induce torpidity in them 

 were they liable to be so affected, and which actually do produce 

 such a result in animals known to be endowed with this consti- 

 tutional peculiarity. 



I myself have repeatedly seen large numbers of swallows, 

 Hirundines rustics, reduced to the necessity of alighting in fields 

 for the purpose of obtaining some of the insects which a low 

 temperature had constrained to seek refuge among the herbage, 

 and so greatly were they enfeebled as almost to suffer themselves 

 to be taken with the hand. 



Severe and long-continued frosts, especially when accompanied 

 with snow, often prove very fatal to the redwing, Turdus iliacus, 

 and under such circumstances, I have occasionally found indivi- 

 duals of this species dead or in a dying state. 



Numerous instances of a similar kind might be selected from 

 works on natural history, but one will sufiice. I quote from * A 

 Catalogue of the Norfolk and Suffolk Birds, with Remarks, by 

 the Bev. R. Sheppard and the Bev. W. Whitear,' published in 

 the ^ Transactions of the Linnsean Society,' vol. xv. : — " The fol- 

 lowing extraordinary circumstance in the natural history of the 

 swallow, which occurred at Christ Church, Ipswich, (the resi- 

 dence of the Bev. Mr. Fonnereau,) very forcibly illustrates the 



