MILLER CONTRIBUTIONS FROM ANATOMICAL LABORATORY. 237 



have shown, the shape of the cells and the conditiou of relax- 

 ation of their bounding lines is dependent on tension. 



With the increase in age of preparation the appearance of the 

 epithelium was found to change. Xiimerous granulations ap- 

 peared and the nuclei were seen in clear relief. The stronger 

 the solution of nitrate of silver used the larger and more nu- 

 merous were the granules. 



Owing to these phenomena it was found advisable to study all 

 preparations immediately after they had been mounted. In 

 preparations which had been impregnated with a weak solution 

 of nitrate of silver (2 :1000) these granules were usually absent 

 even after being kept for some months. In some specimens nu- 

 merous cast-off epithelial cells were found, l)ut in no case was 

 anything at all comparable to Klein's ^'germinating cells" found. 



Stomala. Klein (7) accepts the conclusions of v. Reckling- 

 hausen (19) wdiich he says were reiterated by Ludwig and 

 Schweigger-Seidel (13), Dybkowsky (4), Schweigger-Seidel 

 and Dogiel (21), and Bohm (3). Klein himself declares that 

 "we can only consider those figures as stomata which lie in the 

 center of radially disposed, relaHvely large endothelial cells." 

 "All other indications," he continues, "are very probably only 

 joung cells formed by division of the larger." He also admits 

 that it is a difficult question to decide whether certain structures 

 can be called stomata or not. 



Ellenberger (5) practically agrees with this view, adding that 

 "these numerous stomata are bounded by the free ends of the 

 imbedded nuclei." Ranvier (17), on the contrary, denies the 

 existence of stomata and regards these structures as nothing else 

 than "small inter-endothelial spots." Arnold (1), in his earlier 

 writings speaks of stomata and stigmata ; but in his later, he 

 declares that "stigmata are nothing else than scattered diffusions 

 -of the fluid or semi-fluid inter-cellular substance." 



Klein in a later publication than the one mentioned above 

 (8) and especially in his joint publication with Xoble Smith (9) 

 goes much farther than any of the previous investigators, not 

 only as to the classification of stomata, but also regarding the 

 importance which he ascribes to them. They divide stomata 



