MICROSPORIDIA — PARASITIC IN MOSQUITOES 161 



The nuclear division during schizogony in the present species 

 is not of as simple a type as was observed by the writer ('16) in 

 Nosema bombycis or in Nosema baetis described below. The 

 chromatic substance seems to undergo a thread formation (fig. 

 3) which finally becomes divided into two groups (figs. 5, 6). 

 No achromatic figures were recognizable. Further data are 

 missing on account of rather advanced state of the parasites. 

 Debaisieux seems to have noticed a similar phase of the nuclear 

 change (compare his figures, especially fig. 48, with fig. 6 of the 

 present paper). 



The sporont is a spherical or slightly elongated body and its 

 protoplasm is more or less vacuolated than that of the schizont. 

 Its nucleus divides into two (figs. 25 to 27), the body remaining 

 rounded. The nuclei further divide simultaneously, producing 

 four nuclei (figs. 28, 29) . The protoplasm divides also into four 

 pyriform bodies which are connected at the center of the sporont 

 (figs. 30, 32, 33). They sometimes cease to undergo further 

 division and become rounded sporoblasts (fig. 31). Tn most 

 cases, however, these four cells, still connected, undergo further 

 division. Each nucleus divides once more in a plane at right 

 angles to the longitudinal axis of the body, and the protoplasm 

 splits longitudinally into two. Although no division of the body 

 into eight sporoblasts was actually seen, stages such as shown in 

 figure 33, in which one of the nuclei is dividing into two, seem to 

 •justify this statement. Thus finally eight sporoblasts become 

 differentiated which remain united for some time (fig. 35). 

 During these changes, the nucleus is located at the distal end in 

 each dividing form. 



Thus the sporont produces eight (sometimes four) sporoblasts, 

 which are connected by the central mass of protoplasm for some 

 time after the completion of division. 



The sporoblast is an oblong body (fig. 36). The nucleus is usu- 

 ally near the rounded extremity, later moving toward the center 

 of the body. It is generally composed of numerous granules 

 which stain very deeply. When the sporoblast begins to trans- 

 form into a spore, the nucleus divides into two of unequal size. 

 The smaller nucleus is found near one of the extremities, and 



