191 1] Francis Ernest Lloyd 13 



mass coagulates and shrinks during ripening, and may be rapidly 

 coagulated by heat, even before ripening has set in. From the 

 purely histological point o£ view, this substance appears to belong 

 to the group of pectic or mucilaginous substances found in the 

 vacuoles of the mucilage cells of orchids, and probably of the paren- 

 chyma of some fruits, e. g., of the pulp-cells in the persimmon 

 itself. Before passing on to a critical examination of this peculiar 

 " tannin-mass," we shall first consider its visible structure. 



In my previous paper I described certain surface characters and 

 showed that, in addition to lenticular depressions, there may be 

 observed canals which extend from these depressions in various 

 directions. A figure was presented showing these superficial ap- 

 pearances. Inasmuch as the description appHed only to the sur- 

 face of the tannin-mass, it failed to give any idea of the internal 

 structure. I had overlooked the fact that the tannin-mass is pene- 

 trated by a complex System of canals, which are frequently paired 

 (fig. i) and are at many points expanded into variously shaped, but 

 usually oval, cavities having the appearance of vacuoles (figs. 1-3).^ 

 On first discovering these passages, they appeared to be due 

 to the presence of protoplasmic Strands, but the evidence that such 

 is the case is too slight to Warrant this view. It may be that dur- 

 ing the earlier development of the cell some of the canals are so 

 caused, but at this moment the point must be left for future study. 

 At present I argue that they are not to be explained in this way, 

 because of their peculiarities of form and direction, because they are 

 often paired, and because of the number and shape of the cavities. 



These canals and cavities are of great importance in enabling us 

 to understand certain phenomena which otherwise are difficult to 

 explain. They may be observed in tannin idioplasts in the tissue of 

 a still quite hard fruit and must exist for a considerable period 

 previous to this time. The figure (fig. i) presented herewith shows 

 the appearance of a tannin cell which lay in a position favorable 

 for Observation in a small section. The chromatophores and other 

 protoplasmic structures, excepting the nucleus, are omitted in order 

 to reduce the complexity of the drawing. This cell represents the 



* Tichomirow's remark, " II y a aussi des inclusions ovoides ou spheriques 

 de 30 microns ä 65 microns " may ref er to these vacuoles, but his very brief 

 description does not enable me to decide (1904, p. 305). 



