MICROSCOPIC FORMS OF ANIMAL LIFE. 



3 



bursts, and the red pear-shaped bodies issue forth into the water (c), 

 moving freely about by the vibrations oiflagella formed by the drawing- 

 out of their small ends, just as do the flagellated zoospores of proto- 

 phytes ( 231). These bodies, being without trace of either nucleus, 

 contractile vesicle, or cell-wall, are to be accounted as particles of simple 

 homogeneous protoplasm, to which the designation plastidules has been 

 appropriately given. After about a day the motions cease; the flagella 

 are drawn in, and the plastidules take the form and lead the life of 

 Amoeba ( 403), putting forth inconstant pseudopodial processes, and 

 engulfing nutrient particles in their substance (D). Two or more of 

 these amoebif orm bodies unite to form a ' plasmodium ' (as in the Myxo- 



FIG. 279. 



Protomyxaaurantiaca:*., encysted statospore; B, incipient formation of swarm spores, shown 

 at c escaping from the cyst, at D swimming freely by their flagellate appendages, and at K creep- 

 ing in the amoeboid condition; F, fully -developed reticulate organism, showing numerous vacuoles, 

 a, and captured prey, 6, c. 



mycetes, 222); its pseudopodial extensions send out branches which 

 inosculate to form a network; and the body grows, by the ingestion of 

 nutriment, to the size of the original. In this cycle of change there 

 seems no intervention of a generative act, the coalescence of the amrebi- 

 f orm plastidules having none of the characters of a true 'conjugation.' 

 But it is by no means improbable that after a long course of multiplica- 

 tion by successive subdivisions, a sexual act of some kind may intervene. 

 394. Another very interesting 'moneric' type is, the Vampyrella; 

 of which one form (Fig. 280, B) has long been known in its encysted con- 



