456 HYBERNATION OF INSECTS'. 



ter was never lower at night than 48, while in the first 

 week of August it was twice as low as 46, and never 

 higher than 50. a 



As a last resource, the.advocates of the doctrine I am 

 opposing, may urge, that possibly insects may even have 

 their sensations affected by the cold some days before it 

 comes on, in the same way as we know that spiders and 

 some other animals are influenced by changes of wea- 

 ther previously to their actual occurrence. But once 

 more I refer to my meteorological journal ; and I find 

 that the average lowest height of the thermometer, in 

 the week comprising the latter end of October and be- 

 ginning of November 1816, was 43|; while in the week 

 comprising the same days of the month of the end of Au- 

 gust and beginning of September it was only 44f- a dif- 

 ference surely too inconsiderable to build a theory upon. 



I have entered into this tedious detail, because it is of 

 importance to the spirit of true philosophizing to show 



a Since the publication of the first edition of this volume, I have 

 had an opportunity of making some observations which strongly cor- 

 roborate the above reasoning. The month of October in the pre- 

 sent year (1817) set in extremely cold. From the 1st to the 6th, 

 piercing north and north-west winds blew; the thermometer at Hull, 

 though the sun shone brightly, in the day-time was never higher than 

 from 52 to 56, nor at night than 38 ; in fact, on the 1st and 

 3rd it sunk as low as 34, and on the 2nd to 31 : and on those 

 days, at eight in the morning, the grass was covered with a white 

 hoar frost ; in short, to every one's feelings the weather indicated De- 

 cember rather than October. Here then was every condition fulfill- 

 ed that the theory I am opposing can require; consequently, accord- 

 ing to that theory, such a state of the atmosphere should have driven 

 every hybernating insect to its winter quarters. But so far was this 

 from being the case, that on the 5th, when I made an excursion pur- 

 posely to ascertain the fact, I found all the insects still abroad which 

 I had met with six weeks before in similar situations. 



