120 NATURAL HISTORY 



I will endeavour to get a hen, and to examine. 



Your 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 tho 

 caprimulgus, 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 endeavours to 

 be sure of his facts) can make but slow progress ; and all 

 that one could collect in many years would go into a very 

 narrow compass. 



Some extracts from your ingenious " Investigations of the 

 difference between the present temperature of the air in Italy," 

 &c. have fallen in my way ; and gave me great satisfaction : 

 they have removed the objections that always arose in my mind 

 whenever I came to the passages which you quote. Surely the 

 judicious Virgil, when writing a didactic poem for the region 

 of Italy, could never think of describing freezing rivers, unless 

 such severity of weather pretty frequently occurred ! 



P.S. Swallows appear amidst snows and frost. 



and this in the calcifying segment, and " the rest of the oviduct was dis- 

 posed in close transverse folds and not exceeding two lines in diameter," 

 yet " the ovary, besides a cluster of small ova, contained one ovum about 

 half an inch in diameter, and no doubt ready to pass into the oviduct when 

 disburthened of the egg which it was then perfecting." Mr. Yarrell does 

 not offer any fact to prove the plurality of eggs laid by the cuckoo, but 

 appears to take it for granted, as also does Montagu j and there are so 

 many interesting facts recorded in the ' Zoologist ' and other publications 

 as to place the matter beyond all doubt. T. B.~| 



