162 



PROTOZOOLOGY 



different cells, then paedogamy. The autogamy is of common occur- 

 rence in the myxosporidian spores. The young sporoplasm contains 

 two nuclei which fuse together prior to or during the process of ger- 

 mination in the alimentary canal of a specific host fish, as for exam- 

 ple in Sphaeromyxa sabrazesi (Figs. 244; 245) and Myxosoma cato- 

 stomi (Fig. 243). In the Microsporidia, autogamy appears to initiate 

 the spore-formation at the end of schizogonic activity of individuals 

 as in Thelohania legeri (Fig. 71). 



Fig. 80. Conjugation of Metopus es (Noland). a, early stage; b, first 

 micronuclear division; c, d, second micronuclear division; e, third micro- 

 nuclear division; f, migration of pronuclei from one conjugant into the 

 other; g, large conjugant with two pronuclei ready to fuse; h, large con- 

 jugant with the synkaryon, degenerating pronuclei and macronucleus; 

 i, large exconjugant with newly formed micronucleus and macronucleus 

 j, small exconjugant with degenerating macronucleus; k-m, development 

 of two nuclei, a, X290; b-j, X250, k-m, X590. 



