50 H. ]\r. WOODCOCK. 



certainty in tlie case of C. irregularis. I liave examined 

 serial sections throngli many cysts, but wlietlier these contain 

 sporoblasts just about to be liberated, gametes copulating, 

 zygotes, or spores, tliey are always uniformly filled with tlie 

 same (compare fig. 54). I am strongly of the opinion that 

 C. minchinii agrees equally in this respect, judging from 

 sections like that shown in fig. 55 and also from sections 

 through a spore-containing cyst, in which the spores are 

 closely packed and completely fill the cyst, there being no 

 sign of any unused cytoplasm. I lay emphasis upon this 

 point because of its bearing upon the actual manner in which 

 copulation is brought about (see below, p. 52). 



Fig. 53 h shows a small portion of a section ^ similar to that 

 seen in fig. 53 a, in which this separation of the sporoblasts is 

 taking place. At this moment the cytoplasm has a very loose, 

 irregular, and ill-defined appearance, and it is difficult to 

 represent exactly ; in some places the splitting up is rather 

 more pronounced than in others." Besides the fact that the 

 process of segregation is going on practically uniformly 

 throughout the entire cyst, there is another, most important, 

 point to be noticed. All the nuclei are identical in size and 

 appearance. Brasil (loc. cit.) states that, in both Urospora 

 and Gonospora, the nuclei belonging to the two halves of 

 the cyst — to the two associates, that is — are very different in 

 character and easily distinguishable. That is certainly not 

 the case here. The nuclei in the rest of the section from 

 which fig. 53 h is drawn, and equallj^ in other sections of the 

 series, appear exactly like those shown. 



The gametes. — As soon as the segregated uninuclear 

 portions are thus cut out and separated from one another 

 they become rounded off, and each forms a primary sporo- 

 blast. The primary sporoblasts or gametes in C. irre- 

 gularis are, so far as I can ascertain, quite equal and 



^ This section was stained with iron-lisematoxylin, and tlie chromatoid 

 granules are very obvious. 



2 The " c\itting-out " process is, perhaps, slightly more advanced near the 

 periphery tlian elsewliere. 



