iQii] Francis Ernest Lloyd 31 



occurrence of free tannin outside the tannin-mass cannot be demon- 

 strated. We may, therefore, conclude only that the space between 

 the cell wall and the tannin-mass (the protoplasm has largely 

 disappeared in the case we are considering) is the aveniie of escape 

 of free tannin from the latter, and not a reservoir. This explana- 

 tion, which is not entirely free from points of attack in view of the 

 behavior of the torn cells just described, receives support from the 

 behavior many times noted, that there is a greater extrusion of 

 free tannin from the edge of the opening through which the 

 tannin-mass has been projected, than from the tannin-mass itself 

 (fig. 12). Between the two cases, however, there is a difference 

 which readily catches the eye, but which it is difficult to describe or 

 to illustrate by a drawing. From the torn edge of the tannin-mass 

 from the acetic acid fruit, the escaping tannin appears to be 

 partly composed of fine granules already formed by precipitation 

 inside of the cell wall, and to escape in part in this form; in the 

 other case there is no doubt that it escapes as a Solution. The 

 formation of precipitation membranes in the form of tubes from 

 cells from the acid-treated tissue, however, appears to deny the 

 correctness of this explanation. If, again, the free tannin existed 

 as such between the tannin-mass and the cell wall, this itself would 

 take up some of it and show the tannin reaction, and, though I 

 have observed this to happen in hard fruits heated in a sugar 

 Solution, it was not the case here. 



But if the evidence indicates that there is no free tannin in 

 the Space outside of the tannin-mass, there is no lack of it to show 

 that there is free tannin on the inside. If the tannin escapes 

 through the cell wall, it is impossible to say whether the origin is 

 general or local with respect to the tannin-mass. If, however, the 

 tannin-mass becomes exposed by bursting out through the cell wall, 

 the distinction is evident. Thus, for example, the white, granulär 

 membrane, which forms a short time after the extrusion of the 

 tannin-mass, may completely envelop it (fig. 13) ; on the other 

 hand, it may arise from one or several separate points of the ex- 

 posed surface removed as far as possible from the cell wall (fig. 29). 

 I think that it is proper to conclude that this is to be accounted for 

 by the presence of the canals which I have shown may maintain 



