192 K. R. BENSLEY. 



The decision as to which of these views expresses the condition 

 in the living cell must of necessity rest on the examination of 

 living cells. Before taking up this question, however, we may 

 discuss the significance of these observations in the interpretation 

 of the canalicular apparatus of the animal cell for this inter- 

 pretation does not of necessity imply the assumption that the 

 canalicular structure so demonstrated in the plant cell has a 

 real preexistence in that form in the living cell. We may, on 

 the contrary, treat the technique as an experimental method 

 and discuss the results comparatively on this basis. 



For the demonstration of the vacuolar system of plant cells 

 as a network of canals I have found the following fixing fluids 

 best adapted: 



i. FORMALINE, BICHROMATE, SUBLIMATE. 



Neutral formaline (freshly distilled) 10 c.c. 



Water 90 c.c. 



Potassium bichromate 2.5 gr. 



Mercuric chloride 5 gr. 



2. KOPSCH'S FLUID. 



Potassium bichromate 2.5 per cent, in water 75 c.c. 



Neutral formaline 25 c.c. 



With these fluids, as indicated above, the cells of the root tip 

 show a network of canals, whereas the same tissues fixed in 

 Flemming's solution show, instead of canals, multiple small 

 vacuoles. The same statement holds good for animal cells 

 similarly treated. For example, the epithelial cells of the in- 

 testinal glands fixed in the formaline-bichromate-sublimate 

 mixture, or in Kopsch's fluid, show a beautiful canalicular 

 system, while the same cells fixed in Flemming's fluid show at 

 the site of the canals merely a large number of exceedingly fine 

 vacuoles. Thus whether we accept the multiply vacuolated 

 condition, or the canalicular condition, as the preexisting one 

 in the living cell, the analogy between these structures in the 

 animal and vegetable cell holds. 



On the basis of the similarity in constitution of the canalicular 

 apparatus of the plant cell to that of the animal cell, and of the 

 similarity in behavior of this system when treated by the same 

 methods and an account of the part these canals in the plant cell 



