12 Tannin in thc Fruit of the Persimmon [Sept. 



practice, I have foiind it possible to isolate a single cell, and the 

 conclusions here recorded have been reached largely by the study of 

 such. 



The protoplast proper offers no visible peculiarities, but its rela- 

 tions and structure must be understood in order to comprehend the 

 behavior of that inclusion, the " tannin-mass,"^ with which we are 

 here especially concerned. The protoplasm which lies nearer the 

 cell wall contains the spindle-shaped chromatophores (Lloyd, 191 1, 

 fig. 2) which are orange in color due presumably to Carotin. The 

 nucleus occupies a lateral position. In some places, more often at 

 the end of the cell and in the projecting arms, one or more sap- 

 vacuoles may occur, from which tannin is absent.^ This may be 

 proved by the use of weak iron salts only with circumspection, 

 since the color may, by showing through the vacuole, confuse the 

 Observation. Alkaloids may, however, be used with clear-cut 

 results (fig. 8). Since both the nucleus and the vacuoles usually 

 have dimensions greater than the thickness of the peripheral pro- 

 toplasm, they cause this to project into the interior of the cell. 

 The utricle itself occupies the vastly greater part of the volume of 

 the cell, and contains one or more tannin-masses. The form 

 of the body — assuming it to be single — may be understood if, in 

 Imagination, we should open the cell at one point and pour into 

 the utricle a moulding material and thus obtain a cast of its interior. 

 The cast would then represent the tannin-mass. In point of fact, 

 this body is such a cast, and at this juncture I am emboldened to 

 State my belief that the substance which composes it, aside from 

 the tannin, is analogous to a cellulose hydrate (see Gross and 

 Bevan, 1903, p. 26). 



These peculiar cellulose Compounds decompose spontaneously 

 and, when in aqueous Solution, form a jelly or coagulum which 

 takes the form and volume of the containing vessel. This coag- 

 ulum shrinks slowly, according to the authors mentioned, to 28.5 

 per cent. in 47 days, preserving, meanwhile, the form of the con- 

 taining vessel. The application of heat causes rapid coagulation 

 beginning at 70° C. As will appear, the substance of the tannin- 



^ Howard used this term, and I use it in the same sense. 

 *Went (1886, through af Klercker), and af Klercker (1888), showed that 

 tanniferous and non-tanniferous vacuoles may exist side by side in the same cell. 



