206 The Microscope. 



the nucleus has the appearance of containing a beaded network. 



Methyl green will stain the filament alone ; ammonia and 

 Tiydrochloric acid will make it disappear, and so reveal the 

 membrane of the nucleus, the nucleoli, the real reticulum of the 

 nucleoplasm with its meshes filled with the nuclear enchylema. 

 Wonderful indeed !. Can then the nucleus possess besides this 

 long continuous thread also its own proper reticulum and en- 

 chylema? It seems so. 



In the following communications I shall describe these struc- 

 tures more minutely ; it is here suflficient for my purpose to have 

 arrived at the conclusion that in the epithelial cells of Oniscus 

 murarius the three constituting parts of the cell, the membrane, 

 the protoplasm and the nucleus, possess each a similar structure, 

 •consisting of a reticulum, the meshes of which are filled with a 

 granular substance or enchylema. 



Leydig as before stated, had already observed these cells, but 

 he believed that this structure was peculiar to them alone, but 

 Carnoy proves that this is not an exceptional case ; on the con- 

 trary, he affirms that this is common to ail cells, at least he has 

 found many similarly constructed cells in both kingdoms of 

 ^Nature. 



This structure is especially to be seen during the period of 

 activity of the cell and particularly during the process of cell- 

 division, also during the formation of spermatozoids in the sper- 

 matoblast, etc. 



But this is not all. Najgeli maintains that the organic bodies, 

 and consequently the cell also has its own molecular constitution. 

 It would require too much space to develo}> this subject here, 

 but I would refer the reader to Sach's Text-book of Botany for 

 an exposition of Nsegeli's theory. In the last part of the thesis, 

 it is stated also that " the cell is a living mass." 



By this we mean to say that in the cell, phenomena take place 

 which are peculiar to organic bodies and which are grouped 

 under the comprehensive name of life. These phenomena, 

 although many and various, may be grouped under two head- 

 ings, viz : simple physical movements, and chemical mevements, 

 their object being the nutrition, the growth, and the reproduction 

 or multiplication of the cell. 



In subsequent papers, I shall treat this question moie fully, 

 hut here I wish to state that the protoplasm is not alone con- 



