1912] BARRETT— BLASTOCLADIA 361 



increases, until 40-70 are produced, usually about 60 in average- 

 sized sporangia. About the time the zoosporangium reaches its 

 full size the nuclei arrange themselves about the periphery. A 

 large number of the sections show this condition, which seems to 

 indicate that the zoosporangia rest in this stage. This condition 

 probably agrees with that described above for the living specimen 

 in which the protoplasm is coarsely granular. 



Fig. 29 represents a section of a zoosporangium which is entering 

 the stage of zoospore formation. The large nuclei have become 

 distributed throughout the more coarsely granular protoplasm. 

 The number and size of the deeply staining bodies has increased, 

 while some of them show a vacuolate condition. On some of the 

 nuclei can be seen deeply staining masses of small size. Other 

 nuclei are associating themselves, more or less closely, with some 

 of the larger masses. 



This condition is carried still farther in fig. 30. In a number 

 of cases the nuclei are more or less imbedded in the deeply stained 

 bodies, in others they are still free from them. These stages very 

 probably correspond to the more or less homogeneous stage of the 

 living zoosporangium which just precedes the differentiation of the 

 zoospores. Fig. 30 also shows the beginning of segmentation of 

 the protoplasm. It proceeds from the periphery inward in a more 

 or less radial direction, much as described by Harper (2) for 

 Synchytrium decipiens. The lines of division are first recognized 

 as rows of granules, at first more or less indefinite, but which become 

 more and more apparent until they are seen entirely to outline the 

 spore mass. 



Fig. 31 represents a part of a section of a sporangium in which 

 segmentation is almost complete. The limiting surfaces of the 



in a number of cases have separated. Apparently 



masses 



hich would indicate that 



masses 



formed. Harper 



plasm 

 decipi 



formed 



masses 



