1896.] MICROSCOPICAL JOURNAL. 38T 



plasm surrounding the granules, though usually unstained 

 but by this method stained diffusely red. is seen to pass 

 over into the protoplasm of the shell. The shell is a con- 

 tinuation of the sponge protoplasm, not the granular area 

 at a distance, coming in direct communication with it 

 only at one point. For this reason in certain sections 

 the granular area appears to be free, while the cell of red 

 spongioplasm surrounds it at a distance, attaching itself 

 to the wall of the lymph-space in which the mast-cell lies. 

 Such pictures, examined alone, might lead to the mis- 

 taken assumption that this shell were an independent 

 membrance, lining the lymp-space, or a deposit of mucus 

 on the walls of the same. It is only necessary toknow — 

 and it can always be demonstrated is a good collagen- 

 stain — that in neurofibromata every mast-cell is sur- 

 rounded by a rather regularly rounded lymph-space; 

 lining this in a more or less flattened manner, like endo- 

 thelium, lies the spongy shell, while the granular area 

 lies within this, attached to it at about its midst. 



Since the other structures which exhibit the mast-cell 

 reaction are not generally known, I shall add a few 

 remarks concerning them. The original form of ordinary 

 mast-cells, first recognized by Ehrlich, Avhieh arise by 

 acid decolorization or neutralization (?) of basic dyes is 

 that of a spherical, oval, spindle-shaped or irregularly 

 twisted or branching group of granules, whose connect- 

 ing protoplasm (spongioplasm) and nucleus are colorless 

 and therefore invisible. The same forms are also ob- 

 tained by neutral decolorization perferably polychrome- 

 methyleue-blue and decolorization with the glycerin-ether 

 mixture, or a neutral orcein solution, with this differ- 

 ence, that in the group of granules (red) the nucleus is 

 also stained (blue); the surrounding protoplasm is also 

 generally stained somewhat. 



Besides these generally well-known varieties, there are 

 some which occur less frequently and may be unknown 



