VITAL LIMIT OF EXSICCATION. 



39 



cated worms; (3) worms not showing clitella dried more slowly 

 and endured more exsiccation than those showing clitella. 



i 



Leech. 



The species used for these experiments was Placobdella para- 

 sitica (Say) Moore. Specimens were collected from aquaria con- 

 taining turtles and methods employed were the same as those 

 used for earthworms with the exception that the leeches were 

 kept under water until used. During exsiccation each leech 

 coiled up into a ball-shaped mass containing air, for when they 



TABLE II. 



LEECH, Placobdella parasitica (Say) Moore. 



