402 CORRESPONDENCE OF RAY. 



attend any study, being diverted by pain. It is true of 

 late years I have diverted myself by searching out the 

 various species of insects to be found hereabouts, but I 

 have confined myself chiefly to two or three sorts, viz. 

 Papilios diurnal and nocturnal, beetles, bees, and spiders. 

 Of the first of these I have found about 300 kinds, and 

 there are still remaining many more undiscovered by me, 

 and all within the compass of a few miles. How many, 

 then, may we reasonably conjecture are to be found in 

 England, in Europe, in the East and West Indies, in the 

 whole world. The beetles are a tribe near as numerous 

 as these, and the flies of all sorts not fewer. I have now 

 given over my inquisition, by reason of my disability to 

 prosecute and my approaching end, which I pray God fit 

 me for. You that have more time before you may profit- 

 ably bestow some of your spare hours upon such inquiries, 

 and may probably make useful discoveries, at least may 

 reap a great deal of pleasure and satisfaction in finding 

 out and bringing to light some of the works of God not 

 before taken notice of. So I heartily bid you farewell. 



Black Notley, June 30, 1702. 



NOTE. At the time when this letter was written I was 

 but a novice in the history of insects, particularly of gnats, 

 having begun my strict observations of them but the fore- 

 going spring. In order to the discovery of the process of 

 their generation, I shut up in glasses divers nymphae and 

 aurelise of gnats, with the water in which they were pro- 

 duced ; and after all the aureliae were become gnats, and 

 the nymphae, aurelia?, I found there were other nympha? 

 succeeded ; and, not having seen any eggs in the water, 

 I very inadvertently concluded that those nymphse, or at 

 least the aurelia3 (which I thought might be more perfect 

 animals than I afterwards found them), might lay eggs, 

 and be the parents of those succeeding nymphs. But I 

 soon found my error, and that what my friend Mr. Ray 

 saith in this letter was true, and also discovered the whole 

 process of the generation of gnats^ and that this tribe of 



