60 



THE DAWN OF LIFE. 



is clear or transparent^ and more dense tlian tlie inner 

 miss^ wliicli seems granular. It lias at one end a 

 curious vesicle wliicli can be seen gradually to expand 

 and become filled witli a clear drop of liquid,, and tlien 

 suddenly to contract and expel the contained fluid 

 through a series of pores in the adjacent part of the 

 outer wall. This is the so-called pulsating vesicle^ and 

 is an organ both of circulation and excretion. In 

 another part of the body may be seen the nucleus, 



// 



Fig. 12. Amo&ha. Fig. 13. Actiiiophrys. 



From original sketches. 



which is a little cell capable, at certain times, of pro- 

 ducing by its division new individuals. Food when 

 taken in through the wall of the body forms little 

 pellets, which become surrounded by a digestive liquid 

 exuded from the enclosing mass into rounded cavities 

 or extemporised stomachs. Minute granules are seen 

 to circulate in the gelatinous interior, and may be 

 substitutes for blood-cells, and the outer layer of the 



