252 CORRESPONDENCE OF RAY. 



for the yolk of the egg into the intestine of the young 

 viper ; just as I have seen in young Dog-fish {Scyllium 

 canicula] , in the belly of the old one, haK, or a good part 

 of the yolk hanging out of the body at the infundibulum. 

 It seem to me not at all likely that creatures of the same 

 genus should have a different manner of generation ; and 

 we see this hatching of eggs, properly so called, in the 

 belly, exemplified in cartilaginous fish. 



I have some reason to doubt of what you and Dr. 

 Tyson write concerning adders having no vesiculse semi- 

 nales. A male that I dissected had a long vesicula re- 

 plete with sperm (as I took it to be), like the milt of a 

 fish, extending the whole length of the belly ; but I did 

 not carefully examine it, and therefore might be mistaken, 

 and it might be nothing but fat. 



B. N., June 1, —92. 



Mr. Eat to Dr. E-obinson. 



Sir, — Om' principal physician at Braintree, Mr. Allen, 

 my acquaintance and friend, hath discovered hereabouts 

 fiying glowworms ; and I doubt not but they are every- 

 where to be found, being nothing else but a kind of long- 

 bodied beetle, though they shine not in this country. 

 They answer exactly to Aldrovand's description of the 

 Cicindela volans of Italy. The reason why I mention 

 this is, because this gentleman meeting wdth this beetle, 

 and finding by strict observation that the body of it 

 answered exactly in figure to that of a creeping glow- 

 worm, suspected it to be the male glowworm; and 

 having some creeping glowworms by him, put this 

 animal into a box with one of them, which, after some 

 short time, coupled with it ; but because the box where- 

 into they were put was small and shut, to confirm the 

 experiment, he put a creeping glowworm into an open 



