362 H. S. DAVIS 



V. SUMMARY 



1) The urinary bladder and Wolffian ducts of the squeteague, 

 Cynoscion regalis, contain large numbers of a myxosporidian 

 parasite, Sphaerospora dimorpha, n. sp. 



2) This parasite occurs in two very distinct forms, one of 

 which is disporous, the other polysporous. 



3) Both disporous and polysporous forms ingest solid food. 



4) The spores produced by each form are identical and the 

 number and form of the chromosomes are the same in both cases. 



5) In both disporous and polysporous forms the trophozoites 

 contain both vegetative and generative nuclei. 



6) In the disporous form the generative or 'propagative' 

 cell forms two sporoblasts, each containing six cells, two of which 

 form the sporoplasm, two the capsulogenous cells, while the other 

 two form the spore membrane. 



7) In the polysporous form the generative or 'propagative' 

 cells may form either gemmules or pansporoblasts. 



8) Sporulation in the polysporous form is essentially the same 

 as in the disporous, differing only in unimportant details. 



9) There is no evidence of a sexual process connected with 

 sporulation in either form. 



10) In all probability the only method of multiplicative re- 

 production in the polysporous forms is by the formation of 

 gemmules. 



