250 SOME MINUTE ANIMAL PARASITES 



hosts. The genus Sphczrospora in many respects is 

 like Myxidium, but it has a spherical spore and its 

 two polar capsules lie side by side. Sphceromyxa 

 (Fig. 46), a genus founded by The"lohan, is also 

 nearly allied to these forms, and has a similar tro- 

 phozoite structure, but forms long, curved spores. 

 These parasites may form but few spores at a time, 

 but on occasions numerous spores can be seen 

 within them. 



Before leaving the family Myxidiidse it should be 

 mentioned that while these organisms have definite 



FIG. 46 SPORE OF SPH^ROMYXA : SUTDRAL PLANE HORIZONTAL. 

 FROM THE GALL-BLADDER OF A BLENNY 



pathological effects on the marine fish, among which 

 they are widely distributed, yet they can be equally 

 injurious to fresh-water ones. A recent epidemic in 

 the West of England among dace and trout has 

 been traced to the agency of a Myxidium in the 

 gall-bladder, and an allied species is responsible for 

 the death of golden carp, the gall-bladders of these 

 fish also being the seat of infection. 



The genus Chloromyxum (Fig. 47) possesses a 

 special interest in that it occurs not only in the 

 gall-bladders of several fishes of the shark group 

 (Selachii), but also in the muscles of certain 



