[ 4^5 ] 
Gr thofe which I have found divided, were they fo only 
by any Accident > I could hardly have hoped, that my 
Obfervations would have furnifhed me with Anfwers 
to thefe or the like Queftions : But Worms of this 
fort, which I kept intire, having divided themfclves of 
their own Accord, have made me think, , that this 
Accident fometimes proceeds from their having thruft 
themfelves too far into the Earth, or from that Earth's 
being of too hard and refilling a Nature. . It may there- 
fore.feemthe more fit, that thefe Infeds, whole Bodies 
are very tender, and. liable to be feparated, fhould repro- 
duce what they loft in the manner I have been fpeak- 
ing of. I have farther obferved, that they are fub- 
jed alfo to a fort of Diftemper, analogous to the 
Gangrene, that fometimes rots off.confiderable Parts 
of their Body; which, . however, they recover after- 
wards, like thofe others which have had the fame- 
Parts cut away. 
XII. Another fort of Worm, upon- which I have 
begun to make Trials, is alfo found in the Water. It 
differs particularly from that <1 have been fpeaking 
of, in that it is confiderably thicker. I . have di- 
vided fome of thefe in the Summer Seafon into Two, 
Three, and Four Pieces. Some have recovered the 
Head and the Tail; but that only after the Space of 
Twenty Days, during which they always lay 'like, 
dead. They lived above a Month after, in a State very 
little different, as to outward Appearance ; and after-; 
wards, perifhed, without making any farther Progrefs. 
The confiderable Difference between the Times in 
which the Pieces of thefe laft Worms complete them-, 
fclves, and thofe employed by the former, with the 
greater Difficulty in their Succefs, do they not chiefly 
ptQrv 
