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THE AMEBIC AN NATURALIST [Vol. XLII 



These at first mark out large areas, which, however, become suc- 

 cessively smaller as new furrows are formed at the periphery or 

 strike off from the sides of the older ones. Finally the proto- 

 plasm of the sporangium becomes divided into approximately 

 equal masses around the large surviving nuclei. These masses 

 are the zoospore origins and each develops into a uninucleate 

 zoospore. 



The nucleus first lies at the center of the zoospore origin, with 

 protoplasmic strands radiating out in all directions among the 

 plastids. Granules are present at the bases of the protoplasmic 

 strands close to the nuclear membrane. The nucleus then moves 

 somewhat towards the periphery of the cell and it becomes clear 

 that the protoplasmic strands on that side at least actually 

 extend to the plasma membrane: these strands become arranged 

 in the form of a funnel with the broader end against the plasma 

 membrane. With this stage the zoospore origins clearly exhibit 



A circle of granules, which is nearly twice the diameter of the 

 nucleus, now appears where the broader region of the funnel- 

 shaped arrangement of strands meets the plasma membrane. 

 From earlier stages it seems probable that these granules pass 

 along the strands as organized bodies from the neighborhood of 

 the nucleus; they certainly arise within the cytoplasm. The 

 granules in the circle finally fuse with one another to form a 

 firm ring, which lies in the plasma membrane or just under it; 

 this ring is the belpharoplast. The blepharoplast later splits 

 into two rings, one immediately below the other, and the circle 

 ^ limerous cilia grows out from the lower. The nucleus finally 



ori^n oT?h im H°T nt T^^ ^ ^ ^ ^ hht ° ry ° f . the 



it seems clear that the nucleus is concerned in a most intimate 

 nimn i with the development of the blepharoplast. since the 

 numerous grannies, which form the ring, appear to come from 



the polar organization of 

 pear to be present in the 



