34 NATURAL HISTORY 



the middle, when the animalcule is about to divide into 

 two. They swim with a wavering motion, and are mostly 

 found during the spring in small pools in marshes. 



12. MoNAS uva. The grape Monad. — These animal- 

 cules are principally distinguished from the former by 

 their being connected together, like a bunch of grapes. 

 The diameter of a single one is l-10,000th of an inch. 

 Ehrenberg has not demonstrated the existence of the 

 digestive sacs in this species. 



These animalcules have some resemblance to the 

 Gonium pectorale, but the clusters are smaller, and more 

 irregularly shaped ; the number in a cluster varies from 

 four to seven or eight. They are the more sluggish the 

 larger the cluster, only rolling about from place to place ; 

 but when separate they swim Mdth great celerity. 



If one of these be placed under favourable cir- 

 cumstances, and watched for some time, it will be found 

 to increase greatly, during which a number of lines are 

 observed on its surface : these gradually strengthen, until 

 at last the individual bursts into a cluster. Found in 

 vegetable infusions. The engraving, Fig. 6, will afford a 

 general idea of this and the preceding species. 



13. MoNAs crepusculum, E. — This species is the same 

 size as the M. termo : it is found in infusions of fungus, 

 especially the mushroom ; and as it will not feed on 

 vegetable colouring matter, its organization has not been 

 demonstrated. 



14. MoNAs enchelis, E. The flask-shaped Monad. — 

 A new species ; l-1200th of an inch in size. 



