

122 MISSOURI BOTANICAL GARDEN 



view to the detection of tannin, they offer no points of strik- 



1 



from 



neighboring parenchyma only by their size, and in this re- 

 spect resemble the primordia of the steroids, which lie, also 

 in a layer, between the tannin cells and the epidermis. 

 Both the former and the stereid primordia are paren- 

 chyma cells which become secondarily specialized, and both 

 have this in common also, that once their peculiar content 

 is laid down, it remains unchanged: namely, in the tannin 

 cells, tannin of the fixed variety, and in the stereids, cellulose 

 and lignin. 



What appears however in this condition as a simple peri- 

 pheral layer of protoplasm, must be in a living condition, 

 as shown by the proper reagents, protoplasm imprisoning a 

 solution of tannin. Alcohol acetic material, even after pro- 

 longed treatment, does not seem to be depleted of the tannin, 

 for upon the addition of methyl blue, a tine, flocculent pre- 

 cipitate is discoverable, occupying the whole of the interior 

 vacuole. Material treated with copper acetate displayed a 

 variety of curious forms of solid tannin-copper compound, 

 and these are, I believe, to be regarded as artefact, Thus, 

 sometimes a coarser or finer network of tannin forms a 

 sponge-like mass, filling the interior; or into this may ex- 

 tend, from a solid, continuous lining, arms of the same ; 

 or the whole interior may be filled with a vacuolated mass; 

 or finally it may appear as a complete, homogeneous lump 

 filling the whole of the cell as seen in ethyl nitrite material, 

 as well as in that prepared by other reagents. In these con- 

 ditions, one may hardly discover the protoplasm which is 

 responsible for the secretion from this, and for this purpose 



m< 



salts for color effect, is rea 

 methyl blue in this regard. 



Much better is 



method 



injustice, I may add that sometimes a quite fine precipitate 

 is to be seen, though the protoplasm is still not to be success- 

 fully differentiated to the eye. 

 To return to the anatomy of the tannin idioplast layer. 



