LATTICE WORKERS, OR POLYCYSTINA. 83 



readily perceive that it is produced by a mechanical 

 and not a special vital agency." 1 



Up to the period of the publication of the Challenger 

 reports, the following was considered as the sum 

 of our knowledge of the reproduction of the Poly- 

 cystina : 



It was not assumed that we had any evidence in 

 favour of sexuality in the reproduction of these little 

 animals, or, in fact, any supposition of sexuality in a 

 group of such simple organisation as that to which 

 they belong. There was, nevertheless, reproduction 

 after a distinct type, associated with what have been 

 termed the " yellow bodies " of the sarcode. Both 

 in the animal of the Foraminifers and of the Poly- 

 cystins these " yellow bodies " are found, to which 

 Dr. Wallich was the first to apply the name of sarco- 

 blasts, with the view of distinguishing them from 

 other corpuscles of a similar appearance. These, he 

 contends, are the true rudiments of the young Fora- 

 minifera and Polycystina, and probably of all 

 Rhizopods. " And whereas/' he says, " in the case 

 of the marine and fresh-water genera, I have been 

 enabled to collect sufficient data to prove that these 

 bodies, although developed within the parent pro- 

 toplasm, become ultimately extruded therefrom, and 



1 " On the Rhizopoda," by Dr. G. C. Wallich, in Monthly 

 Micro. Journ., vol. i. (1869), p. 233. 



G 2 



