STUDY OF THE GENICULA OF COBALLIN.E, 33 



obliquely upward and outward and protrude into the medulla of the 

 primary gen icula in the mode of emergence through cortical layers 

 (fig. 8). 



The Difference in the Properties of the Cell-walls 

 of Articular and Genicular Cells. 



It was not the aim of the present paper to give a discussion in 

 detail concerning the chemical properties of the genicular celJs. In 

 the course of study, however, some points which might interest the 

 reader in some measure have been noticed about the differences in the 

 properties of the cellwall of the articular and the genicular cells. 



The calcareous matter is in the cellwalls of the articular cells. 

 This has already been remarkable by former observers. The middle 

 lamella seems especially rich in such matter. Although positive proof 

 is lacking, this view is held from a microchemical examination of the 

 Cellwall, as will be described below. The mineral is in the form of 

 line ingredients mixed with other substances. 



The cellwall of the genicular portion proper and the epidermal 

 cells are entirely free from calcareous matter. The reproductive cells 

 are, of course, similary free. 



The extragenicular portions of the genicular cells, and the 

 articular cells, except the epidermis, have a calcified cellwall. 



lïrietly speaking, the cellwalls of the cells of the Cwallinœ 

 consist essentially of a compound of cellulose, gélose and lime. 

 The proportion of the components varies according to the parts of 

 the fronds. The energetic cells, such as epidermal cells of the grow- 



1). Nelson and Duncan. 1. c. p. 199. and p. 205. 



