﻿1903] NUCLEAR MEMBRANE 3 1 7 



I 



lymph just as the tonoplast is formed by the cytoplasm coming 

 in contact with the cell sap. 



The karyolymph is no more permanent than the cell sap, and 

 the nuclear membrane is.no more permanent than the tonoplast. 



As the nuclear membrane is of cytoplasmic origin, it is 

 regarded as the inner limiting membrane of cytoplasm rather 

 than as a constituent of the nucleus. 



Although the chromatin granules found in the cells of the 

 Cyanophyceae and Bacteria are surrounded by neither karyo- 

 lymph nor membrane, these granules nevertheless represent the 

 nucleus, since every highly organized nucleus passes through a 

 stage in its development when it consists of nothing but 

 chromatin. 



It is further suggested that the primitive nucleus probably did 

 not secrete a karyolymph and therefore no nuclear membrane 

 was formed. 



Stanford University, 



California. 



LITERATURE CITED, 



- BuTSCHLi, '90: Ueber den Bau der Bacterien und verwandter Organismen. 



Leipzig. i8go. 

 — ■ 'q2 : Untersuchungen liber mikroskopische Schaume und das Proto- 



plasma. Leipzig. 1892. 

 '96: Weitere Ausfuhrungeri liber den Bau der Cyanophyceen. und 



Bacterien. Leipzig. 1896. 

 Fischer, '91 : Die Plasmolyse der Bacterien. Ber. Sachs. Gesell. Wiss. 



Math.-Phys. 1891. 



*97 : Untersuchungen iiber den Bau der Cyanophyceen und Bac- 

 terien. Jena. 1897. 

 HiERONYMUs, *92 : Beitrage zur Morphologic und Biologie der Algen. 



Cohn's Beitrage zur Biologie der Pflanzen 5:461. 1892. 

 Lawson, '98 : Some observations on the development of the karyokinetic 

 spindle in the pollen mother-cells of Cobaea scancie?is. Proc. Cal. Acad. 

 Sci. in. I : 169. 1898. 



00 : Origin of the cones of the multipolar spindle in Gladiolus. 



BoT. Gaz. 30: 145. I9GO. 

 Macallum, '95 ; On the distribution of iron compounds, other than hcemo- 

 globin and hnsmatins, in animal and vegetable cells. Quart. Jour. Micr. 

 Sci. 38: 175, 1895, 



