CiiAr. Vli.] 



LEECHES. 



305 



to degenerate into ulcers, wliicli may lead to the loss of 

 limb or of life. Both Marshall and Davj mention, 

 that dm'ing the marches of troops in the mountains, 

 when the Kandyans were in rebelhon, m 1818, the sol- 

 diers, and especially the Madi-as sepoys, with the pioneers 

 and coohes, suffered so severely from this cause that 

 numbers of them perished.^ 



One cu"cumstance regarding these land leeches is re- 

 markable and unexplained ; they are helpless without 

 moisture, and in the hills where they abound at all 

 other times, they entirely disappear during long droughts ; 

 — yet re-appear instantaneously on the very first fall of 

 rain ; and in spots previously parched, where not one 

 was visible an hour before ; a single shower is sufficient 

 to reproduce them in thousands, lurking beneath the 

 decaying leaves, or striding with rapid movements 

 across the gravel. Whence do they re-appear? Do 

 they, too, take a " summer sleep," hke the reptiles, 

 molluscs, and tank fishes, or may they be, hke the 

 Rotifera, dried up and preserved for an indefinite period, 

 resuming their vital activity on tlie mere recurrence of 

 moistm^e ? 



Besides the medicinal leech, a species of which ^ is 



1 Davy's Ceylon, p. 104 ; Mak- 

 shall's Ceylon, p. 15. 



^ Hirudo smu/tiisorba. The paddi- 

 field leech of Ceylon, used for siu'- 

 pical piu-poses, has the dorsal siir- 

 foce of blackish olive, with several 

 lougitudraal stiife, more or less de- 

 fined ; the crenated margin yellow. 

 Tlie ventral surface is fulvous, bor- 

 dered laterally with olive ; the ex- 

 treme margin yellow. The eyes are 



JIliiJiL 

 liiiiiiiiiiiiiiii 

 liwifr 



ranged as in the common medicinal 



VOL. I. •: 



leech of Europe ; the four anterior ones 

 rather larger than the others. The 

 teeth are 140 in each series, appearing 

 as a single row ; in size diminishing 

 gi-adually from one end, veiy close 

 set, and about half the width of a 

 tooth apart. When of full size, these 

 leeches are about two inches long, 

 but reaching to six inches when ex- 

 tended. Mr. Thwaites, to whom I 

 am indebted for these particulars, 

 adds that he saw in a tank at Colonna 

 Corle leeches which appeared to him 

 flatter and of a darker colour than 

 those described above, but that he 

 had not an opportimity of examining 

 them particularly. 



Mr. Thwaites states that there is 

 a smaller tank leech of an olive-green 

 colour, with some indistinct longi- 

 tudinal strioe on the upper surface ; 



