435 



2 fi in breadth (Fig. 2). They were oval or pear-shaped, having a single 

 polar capsule situated at the smaller end. No details of the latter nor 

 even its exact shajje could be made out, owing to the minute size of the 

 spore. Towards the broader end of the spore (in some cases there was 

 no observable difference in the size of the two ends) there was often 

 visible a clear, rounded space, looking like a vacuole, and in most 



Fig. 3. 



Pig. 4. 



Figs. 3 and 4. Division-stages (?) in formation of spore. 



instances there was -in this a central dot. Between this and the polar 

 capsule was a small mass of protoplasm, in which in very favourable 

 specimens it was possible to detect two minute nuclei. 



Lying in the reticular substance between the cysts constaining ripe 

 spores were a certain number of others filled with small, rounded bodies 

 (Fig. 1, lower part.) which appeared to be the final sporoblasts the stage 

 just before the formation of the spore-coat. These little bodies were 



Fig. 5. 



Fiof. 6. 



Figs. 5 and G. Fragmentation of individual and (?; commencement of endogenous 



spore-formation. 



usually provided with a single nucleus and were somewhat smaller than 

 the mature spore. In one or two cases they were provided with two 

 minute nuclei, lying close together. Whether the single nucleus usually 

 divides before the spore is formed, I cannot say. The material available 

 being small in amount and already fixed and embedded , observations 

 of developmental stages were necessarily fragmentary. A few of those 

 which preceded the sporoblasts just mentioned were visible, but the 



28* 



