758 



ORDER: ACTINOMYXIDIIDA 



of cytoplasm (spongioplasm), in which are embedded, in three columns 

 of eight, twenty-four sporozoites. In addition, the spongioplasm contains 

 three nuclei. The spongioplasm, either intact or segmented into several 



Fig. 325. — Diagram of Life-History of Triactinomyxon ignoUim. (After 

 MACKINNON AND Adam, 1924, FROM THE Quavt. Jourti. Mic. Set.) 



1. Sporozoite. 

 2-6 Formation of pansiiorocyst (3' to 5' stages in T. legeri given as alternative). 

 7-11. Formation of gametes and their reduction bodies (black dots). 



12. Union of gametes. 



13. Zygote and subsequent nuclear divisions (r.n., residual nuclei; g.»., nuclei of sporojjla.smic 



mass; p.c.n., nuclei of polar capsule cells; sp.n., nuclei of sporal envelojje). 



14. Young sjiore. 1.5. Ripe spore. 



masses, moves from the region of the polar capsules towards the point of 

 origin of the rays, where a pore is probably present. Meanwhile, the 

 twenty-four sporozoites unite in pairs, giving rise to twelve binucleate 

 amoeboid bodies. The nuclei of these, though they may come into contact 



