34 ART. li-K. YENDCk 



ing portions, the periphery, or the circum genicular cortex, fcave a 

 larger percentage of the pectin compound than of the cellulose. In 

 this respect the growing points of the land plants furnish us an illus- 

 tiious parallel. The middle lamella, especially at the extragenicular 

 portion, and the connecting plates between the cells, are richer in the 

 pectin compound. In phanerogamic cells we have calcium pectate in 

 the middle lamella. In the present study the writer was not able to 

 determine whether the middle lamella contained the mineral in the 

 form of calcium pectate or calcium carbonate. Any how, the middle 

 lamellae of the articular cells, as in the case of the phanerogemic cells, 

 are very rich in pectin compound. 



The cellwall of the genicular portion proper has several diverse 

 characters. By iodine it gains a deep bright yellow colour, almost 

 brownish. So far as the ordinary cellulose reagents are concerned, the 

 cellwall of this portion gives no reaction of cellulose. It is not a 

 chitinous substance. Probably the cellulose reaction might have 

 been retarded by some compound other than the pectin. The middle 

 lamella of this portion gives also a distinct reaction of a pectin com- 

 pound. This leaves us in doubt whether a trace of calcium compound 

 occurs there or not, although we can by no means detect it. 



The pectin compound in the cellwall is in the form of gélose as 

 in the other algal members. 



The cellulose reaction is not discernible before the i> - elose has 

 been dissolved. But the gélose reaction is clearly visible without any 

 treatment beforehand. 



When the preparations are treated with 50% hydrochloric acid 

 for 12-2-1 hours, both the cellulose and the gélose reactions begin to 

 appear. In these ruthenium red stains the primary cellwall of all 



1). The study has been uiade upon preparations cut by microtome in the thickness of 3 — 4\l. 

 The object is imbedded, alter decalcifying iu 1'krenys fluid, in 5'i° paraffin. 



