236 NATURAL HISTORY 



revived and came forth ; some bees swarmed in this neigh- 

 bourhood ; the old tortoise near Lewes, in Sussex, awakened 

 and came forth oat of its dormitory ; and, what is most to 

 my present purpose, many house swallows appeared, and 

 were very alert in many places, and particularly at Cobham, 

 in Surrey. 



But as that short warm period was succeeded, as well as 

 preceded, by harsh severe weather, with frequent frosts and 

 ice, and cutting winds, the insects withdrew, the tortoise 

 retired again into the ground, and the swallows were seen 

 no more until the 10th 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 mat- 

 ters 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 fourth 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 Oc- 

 tober, 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 flit- 

 ting 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 profound est 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 



