The Natural History of Selborne 287 



winds, the insects withdrew, the tortoise retired again into the ground, 

 and the swallows were seen no more until the loth of April, when, 

 the rigour of the spring abating, a softer season began to prevail. 



Again ; it appears by my journals for many years past that house- 

 martins retire, to a bird, about the beginning of October ; so 

 that a person not very observant of such matters would conclude 

 that they had taken their last farewell ; but then it may be seen in 

 my diaries also that considerable flocks have discovered themselves 

 again in the first week of November, and often on the 4th day 

 of that month only for one day ; and that not as if they were in 

 actual migration, but playing about at their leisure and feeding 

 calmly, as if no enterprise of moment at all agitated their spirits. 

 And this was the case in the beginning of this very month ; for on 

 the 4th of November, more than twenty house-martins, which, in 

 appearance, had all departed about the 7th of October, were seen 

 again for that one morning only sporting between my fields and 

 the Hanger, and feasting on insects which swarmed in that 

 sheltered district. The preceding day was wet and blustering, but 

 the 4th was dark, and mild, and soft, the wind at south-west, and 

 the thermometer at 58^ ; a pitch not common at that season of the 

 year. Moreover, it may not be amiss to add in this place, that 

 whenever the thermometer is above 50, the bat comes flitting out in 

 every autumnal and winter month. 



From all these circumstances, laid together, it is obvious that 

 torpid insects, reptiles, and quadrupeds, are awakened from their 

 profoundest slumbers by a little untimely warmth ; and therefore 

 that nothing so much promotes 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. 1 I am, &c. 



1 In such cases the birds on their way south are probably tempted a little north 

 again for a short period by an increased temporary supply of food-stuffs. ED. 



