26 



IN VERTEBRA TE MORPHOLOG T. 



the pseudqfilaria, and this, gradually losing its motility, de- 

 velops into the adult form. 



B 



PIG. 12. REPRODUCTION OP GREGARINE (from 



1. Clepsidrinablattarum in conjugation; ck = ectosarc, en = endosarc,c?f = 



cuticula, pm = anterior portion, dm = posterior portion, n = nucleus. 



2. Cysts in transformation into pseudonavicelke; pn =- pseudouavicelloe; 



rk = residual protoplasm . 



3. A, a pseudouavicella strongly magnified; B, the same divided into spores, 



sk; n = nucleus, rk = residual protoplasm. 



2. Order Myxosporidia. 



The Myxosporidia are found almost exclusively parasitic 

 in Fishes, affecting principally the skin, but also occurring 

 in the internal organs, such as kidneys, spleen, and urinary 

 bladder. They consist of irregularly-shaped masses of pro- 

 toplasm, sometimes reaching a length 0.1 mm., but usually 

 falling considerably short of this size. Frequently they are 

 enclosed in cysts developed from the tissues of the host, but 



