THE RADIOLARIA. 



83 



or "vacuoles," which, rhythmically, become distended with 

 water, and are then obliterated by 'the contraction of the sur- 

 rounding protoplasm. But in the Actinophrys (or more 

 properly Actinosphcerhim) Eichornii (Fig. 4), the central 

 part of the protoplasm is distinguished from the rest by con- 

 taining a number of endopiasts. It thus leads to the Badiola- 

 ria (Polycistina of Ehrenberg), the simplest forms of which 



2fc_ ' 



Fig. A. — Actinosph&rium. Etchhornii (after Hertwig and Lesser, " Ueber Rhizopo- 

 den,"' Schulze's Archiv, 1876). 



I.--The entire animal; c, c, contractile vacuoles. 



II.— Part of the periphery much magnified; o, a, a, pseudopodia with stiff axial sub- 

 stance ; n, nuclei or endopiasts. 



III. — A very young Actinosphcerium, with only two nuclei and two pseudopodia, 

 much magnified. 



consist essentially of a myxopod provided with filamentous, 

 radiating, and often anastomosing, pseudopodia. The centre 

 of the body is occupied by a capsule filled with protoplasm ; 



