PARASITES OF NERVOUS TISSUE 279 



move away to start new infections in other parts of 

 the nervous system of the host. 



The organism is well adapted for parasitism in 

 the special host in which it is found, but it has not 

 been determined how it can be transferred from host 

 to host. Cephalodiscus nigrescens is Antarctic, and 

 consequently little material could be obtained for 

 study, nor could living material be examined. But 

 even were such available, the solution is not less 

 easy. The angler fish, Lophius, often has micro- 

 sporidian parasites belonging to the Glugeidae on the 

 bases of its nerves, and the fish is a common one, 

 yet the mode of transference of the microsporidian is 

 unknown. It is possible that the spores are set free 

 when the host disintegrates after death, and that they 

 are then ingested by other fish, but so far no proof 

 of it has been afforded. Similarly, it has been sug- 

 gested that the decay of the infected Cephalodiscus 

 host liberates the spores of Neurosporidium. It 

 would be easier for the spores of Neurosporidium to 

 reach a new host than it would be for those of the para- 

 site of Lophius, since the Cephalodiscus live in colonies. 



Rhinosporidium and Neurosporidium are two mem- 

 bers of a group where each pansporoblast produces 

 numerous spores. A simpler set of allied forms is 

 known in which the body divides into pansporoblasts, 

 each of which forms a single spore. This second 

 series forms one division of the group known as the 

 Haplosporidia, Neurosporidium and Rhinosporidium 

 being the second group. The simpler members of 

 the Haplosporidia occur in worms, in the body 

 cavities of Rotifers, and in some of the Crustacea, 



