158 NATURAL HISTORY 



LETTER XXXVI. 



TO THE SAME. 



DEAR SIR; Sept. 1771. 



The Summer through I have seen but two 

 of that large species of bat which I call 

 vespertilio altivolans, from its manner of 

 feeding high in the air : I procured one of 

 them, and found it to be a male : and made 

 no doubt, as they accompanied together, 

 that the other was a female : but, happen- 

 ing in an evening or two to procure the 

 other likewise, I was somewhat disap- 

 pointed, when it appeared to be also of the 

 same sex. This circumstance, and the great 

 scarcity of this sort, at least in these parts, 

 occasions some suspicions in my mind whe- 

 ther it is really a species, or whether it 

 may not be the male part of the more known 

 species, one of which may supply many 

 females ; as is known to be the case in 

 sheep, and some other quadrupeds. But 

 this doubt can only be cleared by a farther 



