164 



THE SCIENCE OF LIFE. 



the building-stone of Paris, and the limestone of the 

 Egyptian pyramids, are composed of their remains. 



In the Radiola- 

 rian order is placed 

 the ActinopJiryssol, 

 (Sun-Animalcule,) 

 ( Fig. 68 ;) many spe- 

 cies of Polycystina, 

 which secrete sili- 

 cious shells, of va- 

 rious shapes and of 

 wonderful beauty, 

 (Fig. 69 ;) and col- 

 onies of gelatinous 



FIG. 68 Acrhophrys sol, in different states. A. In rllizopods, (TJlCllaS- 

 its ordinary sunlike form, with a prominent contractile 

 vesicle, o. B. In the act of division or of conjugation, 

 with two contractile vesicles, o, o. C. In the act of feeding. * */- 

 D. In the act of discharging faecal (?) matters, a and b. 



ule's. 

 A 



To the order Lobo- 

 sa belongs the Amaba 

 princeps, (Fig. 2,) to 

 which reference has 

 been so often made, 

 since it has occupied 

 so important a posi- 

 tion in modern biolo- 

 gy. Chap. II, Sees. 2, 



3,5- 



5. INFUSORIA, or An- 

 imalcules. The term 



FIG. 69. A. Podocyrtis Schomburgkii. B. Rhopa- r . i j 



locanium ornatum. InfuSOHa IS applied tO 



