678 Wisconsin Academy of Sciences, Arts, and Letters . 
each composed of five coils. The dimensions of a typical 
spore are: 
length to end of cavity 11.5 ix 
width to end of cavity 7.0 m 
tail 9.6 fj, 
length of polar capsules 3.5 ^ 
width of polar capsules 2.5 m 
calculated length of po¬ 
lar filaments 1 30-40 n 
Observations on the Structure of the Parasite 
The structure of the nuclei in the myxosporidium and in 
the pansporoblasts presents certain points of interest. These 
nuclei measure from 1.2 /a to 2.3 n in diameter. In the resting 
state they consist of a peripheral layer of relatively large 
Fig. 2.—Stages in the sporogenesis of Henneguya wisconsinensis: a — g, drawn 
from a preparation stained with Delafield’s haematoxylin, X 1300. 
chromatin granules arranged under the membrane and sur¬ 
rounding a clear area which may be either centrally or ec¬ 
centrically situated. In the center of this clear area is an 
endosome or “Binnenkorper” (Fig. 1, b). The division 
stages have not been studied in this species as the material 
appeared not to be promising in this respect. 
The writers have not studied the sporogenesis of this form 
at length, partly because the senior author (Mavor, 1916) 
has already in the press a paper dealing with this phase of 
the life-cycle in another genus, and partly because the ma¬ 
terial did not seem promising in this respect. Certain stages 
have, however, been found in the plasmodium. The propa- 
1 We have since found a spore with an extruded filament measuring 
33/* in a stained preparation. 
