﻿4o6 BOTANICAL GAZETTE [june 



This process is of peculiar interest because of the large size 

 of the nucleus, quite exceptional among the fungi, its peculiar 

 rapid growth and subsequent division, and the problematic 

 taxonomic position of the Chytridiales, which we may reason- 

 ably hope will be cleared up by cytological research. The 

 very few investigations already published on species of this genus 

 in no way detract from the interest of the problem. Two investi- 

 gators, Dangeard ('90) and Rosen ('93), have reported results 

 from Synchytrium Taraxaci DeB. & Wor., which, though not 

 agreeing in detail, reveal conditions entirely unique. They 

 are of such a nature as to demand further investigation and if 

 possible reconciliation with current theories of the nucleus, 

 which suffer violence if the conditions imperfectly reported by 

 these authors really exist. Dangeard employed modern tech- 

 nique, although absolute alcohol and haematoxylin, his favorite 

 fixative and stain, do not seem to be adapted to critical research 

 in this group. 



Dangeard describes the nuclear membrane of Syjichytnuni 

 Taraxaci as granular, the nucleolus also being granular and quite 

 spherical. He says that the nucleus divides by successive biparti- 

 tion,a method of direct division. The membrane inflexes and the 

 daughter nuclei become separated by constriction of the parent 

 nucleus. He figures such division, showing two daughter nuciei 

 together with their clumped chromatin masses grouped on adja- 

 cent sides, the parent chromatin group being evidently con- 

 stricted, as is the remainder of the nucleus. Aside from this 

 curiousmethod of direct division, Dangeard states that the nucleus 

 sometimes divides indirectly, and his fig, 2j shows what he con- 

 siders to be a type of mitosis. From both his text and figures 

 it appears that this mitosis occurs in divisions later than the pri- 

 mary, and that both mitosis and direct division may occur side 

 by side in the same cytoplasm, thus presenting a very unique 

 condition, since it is usual in multinucleate masses of cytoplasm 

 for the nuclei to divide not only by the same mode but also 

 almost simultaneously. Dangeard does not claim to have fol- 

 lowed the mitosis in Synchytrium through its phases, but he men- 

 tions it rather incidentally as a mode seen but not followed in 

 edtail. 



