THE MONADS. 37 



4, 6), &c. ; and the floating coloured slime which some- 

 times appears in the water, is an aggregation of count- 

 less hosts of these beings. One species, which is of 

 a hyaline (glassy or crystalline) appearance, (Monas 

 crepusculum), and but one two-thousandth of a line 

 in diameter, is of a spherical form, and is said to 

 be carnivorous; whitish masses, visible to the naked 

 eye, are often formed by the accumulation of innu- 

 merable myriads of this species. The Monads never 

 vary in form, whether they are in motion or at rest. 

 They increase by self-division either into. two, or four, 

 parts, (pi. n, figs. 3, 7). When this process is about to 

 take place, the granules within the integument, or case, 

 seem to be divided by a transverse line: this gradually 

 becomes more apparent, and at length the containing 

 case itself contracts along the course of this line, and 

 the monad appears double, (pi. 11, figs. 7 b, 8). Both parts 

 now have an impulse to separate, and an entire division 

 soon takes place: the two become perfect individuals, 

 and swim off in opposite directions. 



In the CLOAK MONAD, ( Chlamidomonas), this interest- 

 ing process is beautifully exemplified. Fig. 7, shews a 

 single animalcule, and another dividing into two: and 

 in fig. 3, two Monads are seen separating into four. 

 The same process in another species, (Monas vivipara), 

 is represented in fig. 8. 



