168 ILLINOIS BIOLOGICAL MONOGRAPHS [406 



Nemeczek observed two more different (?) forms. One form found in 

 Lucioperca sandra, tho the size differs from the dimensions given by 

 Schroder, is thought to be identical with the present species. Another 

 form in the branchiae of As pro zingel, which is also to be one and the same 

 species with the present species has the following dimensions: total length 

 35^1, length of spore excluding tail 15/x, breadth 5/i, length of polar capsule 

 6fi, length of tail 20/i. 



HENNEGUYA GIGANTEA Nemeczek 

 [Figs. 527 to 535] 



1911 Henneguya gigantea Nemeczek 1911 : 146-154 



1914 Henneguya gigantea Georgevitch 1914 : 387-409 



Habitat: Branchiae of Lucioperca sandra Cuv.; Apatin, Komitat 

 Bacs-Bodrog, Hungary, Petrograd. Nemeczek mentions that the infection 

 takes place only among young fish. 



Vegetative form: Cysts numerous and of conspicuous size in the free 

 end of branchial lamella. In average, each gill-arch has about 100 cysts 

 which are of creamy color. Young cysts 400 to 450ju in diameter. They 

 gradually begin to increase the size, from autumn until toward the end of 

 spring, during which period, the contents remaining in the stages of pan- 

 sporoblasts formation. Older cysts rounded spindle shape with the length 

 of 4 to 7mm. and the breadth of 2 to 3mm. The connective tissue and 

 epithelial cell layers form the cyst membrane. The connective tissue 

 either simply surrounds the parasite or branches in the surface of the para- 

 site, increasing in thickness and forming more or less enclosed chambers 

 of the parasite. The membrane of the cyst which contains mature spores 

 is usually very thin. Throughout the growth of the cyst, "chromatoid 

 body" is seen in the endoplasm, which appears first as a filiform struc- 

 ture, stained deeply with nuclear stain. Later tl^y gather together and 

 form a compact body, situated excentrically. Fine branches from it 

 become directed toward the surface of the body, anastomosing each other 

 so that a network is formed on the surface of the cyst. The latter develops 

 small ovoidal or columnal bodies (1.2/i long and about \y. wide), which 

 are arranged radially and densely. The number and quantity of these bod- 

 ies increase in proportion to the number of propagative nuclei and they 

 begin to disappear, first in the central portion, then in the periphery, 

 so that in fully grown cysts (in summer months) these chromatoidal bodies 

 are more rudimentary. Differentiated protoplasm is only recognized in 

 young individuals, in which case ectoplasm is homogeneous and endoplasm 

 reticular. Polysporous. 



Spore: Nemeczek gives the following accounts. 



