THE ASEPTIC CULTIVATION OF MYOETOZOA. 67 



disc. When seen on the edge they appear spindle-shaped. 

 They contain from one to six or seven small bodies, which 

 may provisionally be called nucleoli. One finds nuclei con- 

 taining two nucleoli. These nuclei are at times constricted, 

 and suggest stages of division. 



Strasburger (23) studied the division of the nuclei of 

 Trichia fallax during the formation of the sporangia. He 

 succeeded in finding stages which showed karyokinesis. 

 Rosen (39) studied the division of the nuclei in the forming 

 sethalia of vEthalium septic um, but found the division of 

 the nuclei simpler than that described by Strasburger. 



Lister (44) describes the division of the nuclei of zoospores 

 and of the nuclei of the plasraodia by karyokinesis, but also 

 concludes that they divide by direct division. The writer has 

 not been so fortunate as to find nuclei dividing by karyokinesis, 

 although frequent search was made for them. 



The zoospores can frequently be seen to divide and form 

 two zoospores, and to the writer there seems to be evidence 

 that at times the protoplasm of the microcysts breaks up into 

 a number of small segments, and these segments enlarge and 

 develop zoospores. 



The nuclei of Phys. ciuereum are smaller than those of 

 Stemonitis A. They are spherical, containing one or more 

 nucleoli, and are distributed in every part of the protoplasm, 

 but are more abundant in some portions than in others o 



Before concluding the writer wishes to acknowledge the 

 invaluable assistance which he received from Professor Biitschli 

 while pursuing these studies in Heidelberg, also to Professor 

 Wladimir Schewiakoff, then assistant at the laboratory of 

 Heidelberg, for his assistance in the preparation of the 

 plates. 



