CARCHESIUM. 125 



heaps at the bottom, and in double that time all 

 had perished. This species is found principally 

 on duckweed. V. campanula is larger than 

 V. convallaria, and rather brown in colour : 

 it has a bell-shaped body, but truncated in 

 front. The single animalcules may be discerned 

 without a glass ; and a mass of them appears like 

 a bluish matter attached to water-plants. There 

 are several other species, all differing slightly 

 from those mentioned, but having the same gene- 

 ral appearance and habits. 



The next genus is Carc/tesium, and it differs 

 from the last in its imperfect mode of self- 

 division. There is one main stalk, which has 

 the power of being contracted in coils, like that 

 of the last genus ; but it is branched, and each 



M 3 



