84 THE ANATOMY OF INVERTEBRATED ANIMALS. 



this sometimes contains only an oil-globule, at others cells, or 

 nuclei, and crystalline bodies. In the layer of protoplasm 



Fig. b.—Sphcerozoum punctatum.—A, a mass of the natural size ; B. two of the oval 

 central sacs with the colored vesicles and spicula which lie in the investing pro- 

 toplasm, magnified. 





m 



■4- ^,¥ 



Fig. 6.—Sphcerozoum ovodimare (after Haeckel), magnified. 



from which the pseudopodia proceed, cellseform bodies of a 

 bright -yellow color, which have been found to contain starch, 

 are usually developed, 1 and this layer also gives rise to a skele- 

 ton of a horny, or, more usually, silicious character, which 



1 Even after the death of the Radiolarian, these yellow cells are said by Cien- 

 kowsky to thrive and multiply, and the possibility that they may be parasites 

 must be borne in mind. 



