THE SYNCHYTRIAN NUCLEUS 



81 



and the first division occurs, /. Successive simultaneous 

 mitotic divisions follow till the sorus subdivides into 

 sporangia, g, containing a great number of small nuclei. 

 The young zoospores are at first close -packed but, water 



FIG. 21. SYNCH YTBIUM ENDOBIOTICUM, AGAMIC STAGES, a, zoospores, 

 living state ; 6, young parasite nearing host's nucleus ; c, full-grown 

 parasite ready to develope into a sorus, pyramidal heaping of granules ; 

 d, a stage in formation of the sorus, the nucleus beginning to pass 

 through the opening in the capsule ; e, primary soral nucleus, late 

 prophase ; /, the same metaphase, spindle with 5 chromosomes ; 

 g, early stage of segmentation of sorus ; h, zoospores nearly full- 

 grown, the stands joining them become flagella later. After K. M. 

 Curtis. 



being absorbed, they become more loosely arranged and 

 are joined by fine strands which become the flagella entering 

 each zoospore at the point where the blepharoplast is seen. 



6 



