ipii] Francis Ernest Lloyd 37 



and the jelly-like mass extrudes, or migrates into the surrounding 

 medium, either accompanied by the protoplasm or alone. It is 

 probable that this substance contributes to the difficulty experienced 

 by Bigelow, Gore and Howard in fiUering watery extracts. What- 

 ever facts may be brought to Hght by a study of this, and 

 of the associated colloids, which I hold tentatively to be a cellu- 

 löse mucilage. they will assuredly be of interest. 



IV. SUMMARY AND CONCLUSIONS 



A brief setting forth of the views concerning the fate of the 

 tannin during the process of ripening in the date (Ph(rnix) and 

 in the persimmon (Diospyros) shows that the explanations here- 

 tofore advanced are inadequate. The presence of the tannin in ripe 

 fruit, and the absence of astringency have been the basis of the 

 Statement that the tannin is insoluble. The contention here made 

 is, that insolubility of tannin as such is not the fact, but that it has 

 in large part combined with an associated colloid to form an in- 

 soluble colloidal complex. The evidence for this has been sought 

 in the visible behavior of the so-called tannin-mass, in its physical 

 relation to soluble or free tannin in the same cell, and in its be- 

 havior toward chemical reagents. 



The tannin-mass has been shown to have an internal structure, 

 consisting of a System or complex of canals, spherical or sub- 

 spherical spaces, and lacunae which have a definite existence. Their 

 origin has not been shown, but a tentative explanation has been 

 advanced. Their behavior during the maturation of the tannin- 

 cell, and their form relations as a result of the swelling of the 

 tannin-mass, have been described in detail. The complex in ques- 

 tion is broken up, the cavities (having the appearance of vacuoles) 

 often taking a superficial position on the tannin-mass, by internal 

 pressure produced by the swelling of the tannin-mass restricted 

 by the cell-wall. They have been shown not to contain free tannin 

 under normal conditions, but it is probable that they afford paths 

 along which soluble tannin moves under pressure. 



The material called the tannin-mass is shown to be a tannin- 

 colloid complex, the second named term of which appears to be 

 a cellulose-mucilage or allied colloidal substance. 



