386 PROCEEDINGS OF THE ACADEMY OF [June, 



2. Gregarinida: 



Vegetative stage, if intracellular at all, only so at first; adults 



always extracellular. 

 Fertilization anisogamous or isogamous. 

 Fertilized forms always continuously extracellular. 



In the Sarcosporidia, the vegetative stage is intracellular, becoming 

 extracellular only through the destruction of the cells originally 

 occupied. Fertilization is anisogamous and the sexual generation 

 is typically intracellular, becoming extracellular only by accident. 

 Evidently, then, so far as the main characters go, those of the Sar- 

 cosporidia are identical with those of the Coccidiomorpha. It 

 therefore seems allowable to place them in this group. 



Doflein divides the order Coccidiomorpha into suborders, as 

 follows: 



1. Coccidia: 



Sporozoites inclosed in spores. 



Zygotes nonmotile, mostly intracellular. 



2. Haemosporidia: 



Sporozoites always free. 



Zygote, as the ookinete, motile, and migrating into new cells. 



Judging from Erdmann's contribution, the sarcosporidian zygote 

 does not produce spores, but divides directly into what are possibly 

 sporozoites. This would place the Sarcosporidia closer to the 

 Haemosporidia than to the Coccidia. But the fact that the zygote 

 is apparently nonmotile indicates that the relationship with the 

 Coccidia is the closer. Obviously, however, the Sarcosporidia are 

 neither Coccidia nor Haemosporidia, but our very scanty knowledge 

 regarding this phase of their life history prevents us from defining 

 them in the terms used by Doflein for the two other groups. For 

 the present, it seems best merely to consider them to be one of three 

 suborders making up the Coccidiomorpha. 



The Sporozoa may then be reclassified as follows: 



Class Sporozoa. 

 Subclass I, Telosporidia. 



Order 1, Coccidiomorpha. 



Suborder A, Coccidia. 

 Suborder B, Haemosporidia. 

 Suborder C, Sarcosporidia. 

 Order 2, Gregarinida. 



