STRUCTURE, ETC., OF PLEISTOPHORA PERIPLANETH. 625 
digestive juices and contents of the alimentary canal of other 
cockroaches have been as yet unsuccessful. 
CLASSIFICATION OF PARASITE AND Discussion oF ReEsutts. 
With the above facts of the life history of Pleistophora 
periplanete to hand it is possible to classify the parasite 
accurately. Irom the minuteness of the spores, the fact that 
the pansporoblast produces more than two spores, and the 
invisibility of the polar capsule in the fresh state, the parasite 
belongs to the sub-order Cryptocystes of the Myxosporidia 
and the family Glugeidz, which possesses the characters of 
the sub-order. In the fact that the spores are not pear- 
shaped, but oblong with rounded ends, and that the parasite 
is extracellular it differs, however, from the rest of the 
Cryptocystes. It belongs to the section Oligosporogenea 
(Doflein), because the trophozoite produces a single pansporo- 
blast, and the production of numerous spores by the pan- 
sporoblast relegates it to the genus Pleistophora. It is 
this formation by the trophozoite of a single pansporoblast 
instead of a number of them, which removes the parasite from 
the genus Nosema, section Polysporogenea, to the genus 
Pleistophora, section Oligosporogenea. ‘To sum up, the 
classification of the parasite is as follows: 
Class.—Sporozoa. 
Sub-class.—Nkosporipi.! 
Order.—Myxosporidia. 
Sub-order.—Cry ptocystes. 
Family.—Glugeide. 
Section.—Oligosporogenea. 
Genus.—Pleistophora, Gurley, 1893. 
Species.—Periplanete, Lutz and 
Splendore, 1903. 
1 Reasons, based on the life-history of Pleistophora periplanete, for 
objecting to this method of subdivision of the Sporozoa by Schaudinn are 
given on page 626, 
