March, 1908.] On the Cytology of Synchytrium. 277 



ON THE CYTOLOGY OF SYNCHYTRIUM. 



ni. The Role of the Centrosome in the Reconstruction of 



the Nucleus.* 



Robert F. Griggs. 



Introductory. The first paper of this series on the cytology 

 of Sync4aytrium was published by Dr. and Mrs. F. L. Stevens, who 

 took up the study fresh from their remarkable work on the cytol- 

 ogy of the Oomycetes, hoping to clear up the very doubtful rela- 

 tionships of the Chytridiales which as they say "have offered an 

 open field for speculation heretofore and have baffled definite 

 judgments as to their relationships." They soon saw, however, 

 that they had a very large problem on their hands because of the 

 manv anomalous structures encountered which were very diffi- 

 cult to reconcile with the cytology of the higher organisms. They 

 therefore held the "discussion of these structures for a separate 

 paper, the present one being limited to a series of stages which 

 clearly pertain to true mitosis of the primary nucleus." Other 

 pressing work kept Professor Stevens away from Synchytrium, 

 however, and he decided to turn over his material to the present 

 Avriter. Some of the structures he saw he has described in a sec- 

 ond article ('07). With these suggestions as to the interesting 

 features in the cytology of the group, the writer has been fortu- 

 nate indeed in having furnished him ready to work with all of 

 Stevens' material, alcoholic, paraffine cakes and slides, as well as 

 notes of observation on the slides. He is therefore under very 

 considerable obligations to Professor Stevens, who, forced to 

 forego the pleasure of working out these structures personally, 

 has yet followed the study with a keen interest which quite jus- 

 tifies the consideration of this as a continuation of his former 

 work on the same object. 



Before I took up the material, however, Mr. Lon A. Hawkins, 

 formerly fellow in Botany at the Ohio State University, undertook 

 the investigation but was compelled to drop it on assuming work 

 for the government. It was his preparations that were used in 

 this present work and the writer is very considerably indebted 

 to Mr. Hawkins also for his slides. They are beautiful prepara- 

 tions cut from 2 microns thick and stained in Iron Haematoxylon. 

 Stevens's preparations were stained with the triple stain. 



For the rest of the work. Dr. Stevens and I propose to take 

 up in detail, step by step the peculiar cytological structures in 

 this interesting group either separately or jointly as circumstances 



* Contribv;tions from the Botanical Laboratorv of the Ohio State 

 Universitv XXXIV. 



