36 ART. 14-K. YENDO : 



When treated in 50% hydrochloric acid for 48 hours, the gélose 

 reaction becomes fainter. The epidermal layer stains no more with 

 ruthenium red ; the middle lamella at the articular portion in some 

 measure; and the cell wall of the genicular portion pretty strongly. 

 On the other hand the genicular cells are stained deep brown by 

 chloriodide of zinc and the middle lamellae of the articular cells and 

 of the extragenicular portions assume the deepest brown colour. The 

 cellwalls of the articular portions, inclusive of the extragenicular 

 portion, assume a deep violet. The epidermal laver gives no reaction 

 with chloriodide of zinc. 



Keeping 5 days in 50% hydrochloric acid, I observed the reac- 

 tions. None of the parts was stained by ruthenium red. "By 

 chloriodide of zinc the middle lamella stained in deep violet, especially 

 at the extragenicular portion. The cell wall of the genicular portion 

 proper stains in deep brown, but nothing of a violet tone. The pre- 

 paration thus kept was treated with copper ammonium oxide for 48 

 hours. The result was the entire dissolution of the sections except 

 some of the genicular portion proper. This remnant when treated 

 with chloriodide of zinc gives a brownish colour. Some of the pre- 

 parations had been kept in copper ammonium oxide for 20 hours 

 previous to the treatment with hydrochloric acid, the cellwalls of the 

 articular portion were almost all dissolved, leaving the epidermal cells 

 behind. The middle lamella of the genicular cells remained unchang- 

 ed, but the cellwalls were almost gone. 



I would point out some minor details which were met with 

 during the treatments above mentioned, by the staining reactions of 

 anilin blue, haematoxylin, safranin, etc. 



The intercellular space in the articular cells is some times filled 

 by the middle lamella, the so called intercellular substance of DlPPBL; ,J 



1). Die Neuere Theorie iilier d. feinere Struct, d. Pflanzenhiille. 



