'114 SILETirCE OF SIITGING BIED9. 



ing a female during the laying time. If more than one were 

 come down out of the ovary, and advanced to a good size, 

 doubtless, then, she would that spring lay more than one. * 



I will endeavour to get a hen, and examine. 



Tour supposition that there may be some natural obstruc- 

 tion in singing birds while they are mute, and that when 

 this is removed the song recommences, is new and bold. I 

 wish you could discover some good grounds for this suspicion. 



I was glad you were pleased with my specimen of the 

 caprimulgiis, or fern-owl : you were, I find, acquainted with 

 the bird before. 



"When we meet, I shall be glad to have some conversation 

 with you concerning the proposal you make of my drawing 

 up an account of the animals in this neighbourhood. Your 

 partiality towards my small abilities persuades you, I fear, 

 that I am able to do more than is in my power ; for it is no 

 small undertaking for a man, unsupported and alone, to 

 begin a natural history from his own autopsia. Though 

 there is endless room for observation in the field of nature, 

 which is boundless, yet investigation (where a man endea- 

 vours to be sure of his facts) can make but slow progress ; 

 and aU that one could collect in many years would go into a 

 very narrow compass. 



Some extracts from your ingenious " Investigations of the 

 difierence between the present temperature of the air in 

 Italy," &c., have fallen in my way, and given me great satis- 

 faction. They have removed the objection that always arose 

 in my mind whenever I came to the passages which you 

 quote. Surely the judicious Virgil, when wi'iting a didactic 

 poem for the region of Italy, could never think of describing 

 freezing rivers, unless such severity of weather pretty fre- 

 quently occurred ! 



P.S. Swallows appear amidst snows and frost. 



* It may be mentioned in confirmation of the idea of their laying mow 

 Jifcn one egg, that the American cuckoos deposit several. — Ed. 



