Division in the Root of J Ida Faba. 169 



solved by the action of the cytoplasm or dispersed through 

 the latter, so that no remnant is found in the region of the 

 spindle or of the chromosomes. During the time the 

 nucleolar substance is disappearing, the chromatin stains red 

 with eosin and this the author says may be explained by the 

 assumption that the nucleolar substance either unites chemi- 

 cally with the chromatin or penetrates into the meshes of the 

 latter. There is, however, no chemical union with the 

 chromatin and, therefore, the chromosomes probably do not 

 serve to carry it over to the daughter nuclei. 



There are only a few observations which would show that 

 the chromosomes are derived from nucleoli. But most 

 observers agree that the nucleoli disappear more or less during 

 mitosis, and that the chromosomes are not derived from them. 

 As to the mode of transference of nucleolar substance to the 

 daughter nuclei, the author concludes that it is different in 

 different objects. In most cases, the nucleolus disappears. 

 Wager suggests that the chromosomes serve for mechanical 

 vehicles of transportation. Or the nucleolus may become 

 dispersed in the cytoplasm after the nuclear membrane has 

 disappeared and that each daughter nucleus may take up 

 substance from the cytoplasm or produce its own nucleolus 

 from new substance. 



Function of the Nucleolus. — As a relatively large amount 

 of nucleolar substance is found in the growing nuclei, the 

 author concludes that it stands in some connection with the 

 process of nutrition, is either itself nutritive or represents that 

 portion of the nucleus from which all the nutritive material 

 has been extracted, i. e., it is a waste product. Or it may 

 represent accumulations of nutritive material retained in the 

 nucleus as a reserve supply — this last is not very probable. 



Dr. Montgomery suggests the hypothesis that the nucleolus 

 may arise as a functionless inert mass and acquire its activity 

 later. But in all cases the nucleolus would seem to be in 



