THE HADIOLARIA. 



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 Actinosphceriiim) Eichornii (Fig. 4), the central 

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

 taining a number of endoplasts. It thus leads to the RacUola- 

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



zi — :? E* 



Fig. A.-AcUnosphrBrium Elchhornii (after Hertwig and Lesser, " Ueber Rhi^opo- 

 den," Schulze's Archiv, 1876). 



I.--The entire animal; c, c, contractile vacuoles. . v. x-* • i i. 



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

 stance; n, nuclei or endoplasts. , . J i J ^;„ 



ni.— A very young Actinosphoerium, 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 bv a capsule filled with protoplasm ; 



