Division in the Root of Vicia Faba. 173 



the spores of Saccharomyccs, as observed by Wager, is a 

 strong argument in favor of the view here put forward. The 

 author's own observations on the ascospores of Tuber astivum 

 confirm this. He has observed, that at first the nuclei 

 formed in the ascus are large, and contain a network of 

 chromatin, in which a few nucleoli stained with acid anilin 

 dyes, are imbedded. The nucleus enlarges, the chromatin 

 disappears, whilst the nucleoli increase in size and number, 

 and now exhibit an affinity for basic stains. In this process, 

 there is probably at first a transference of chromatin into 

 nucleoli and afterward a bodily transference of these latter 

 into nuclei. 



In all these cases, if we admit the hereditary functions of the 

 chromatin, it is scarcely possible to deny it to the nucleoli. 



My own observations were made on the cells in the grow- 

 ing apex of the root of the broad bean (Vicia Faba). 



Methods. 



As fixatives chromic and chrome-acetic acids were employed, 

 both of which gave excellent results. These solutions are 

 washed out with water till all the yellow color has disap- 

 peared. The material is then gradually passed through alco- 

 hols of increasing strength into pure alcohol. As a clear- 

 ing fluid, oil of cedar was used, as it is less liable to cause 

 shrinkage, than does xylol. First the material was put into 

 a mixture of the oil and pure alcohol, next into pure oil, 

 thereafter into paraffin, several changes in this last being made 

 to insure complete elimination of the oil. All changes from 

 one solution to another must be made gradually, as for 

 example, from the alcohol to the oil. Sections were cut on 

 the microtome with a feed of six ,«. All staining was done 

 on the slide ; the best stain employed, and the one from 

 which all sketches have been made was iron haematoxylin 

 and Bordeaux red. 



