400 CORRESPONDENCE OP RAY. 



volumes, which hath engrossed almost my whole time for 

 two whole years. Besides, I have a little book now 

 printing at Ley den, in Holland, entitled ' Methodus 

 Plantarum emendata et aucta.' 



An account of your observations about other aquatic 

 insects would be very acceptable. 



As for books about insects written in, or translated 

 into, Latin, I know none but Aldrovand, Mouffet, John- 

 son, and Goedartius, except Malpighius 'de Bombyce,' and 

 Dr. Lister 'de Araneis.' The best general history or ac- 

 count of insects is that of Swammerdam, written in Low 

 Dutch, and translated into French. 



The small worm you mention and describe, I have 

 often met with among the viscera and intestines of ani- 

 mals and elsewhere, but never attempted the discovery 

 of its manner of generation, and do guess it would be a 

 very hard task to find it out. 



Your discovery of the long-beating death-watch I read 

 the account of in the ' Philosophical Transactions,' soon 

 after the publication of it, with great satisfaction; its 

 noise is more agreeable to the leisurely and constant tick 

 of the death-watch commonly observed than that of Mr. 

 Allen's. It is time that I put a period to this letter, the 

 remainder being only that I am, 



Sir, 

 Yours in all offices of love and service, 



JOHN RAT. 



Dr. SHEEABD to Mr. RAY. 



SIR, I forgot in my last to answer your query about 

 corymbiferous plants. Mr. Bobart told me Dr. Tourne- 

 fort's making Bidens a distinct genus was a false notion ; 

 for the seeds of those plants (as of many others of the 

 CorymbifercB] had each four spinulse, though two of them 

 generally fell off before they were ripe. He says all those 

 that have quadrangular seeds have four spinula3, which 

 in many plants fall all off, in others only two remain. 

 London, June 11, 1702. 



