18 THE GUSTATORY ORGANS, BY TH. W. ENGELMANN. 



and the thick cell wall in consequence forms well-marked longitudinal 

 folds. By acids, especially acetic acid and perosmic acid, the 

 protoplasm of the goblet-cells is rendered much more cloudy than the 

 ordinary epithelial cells of the lingual surface. These cells must not 

 be confounded with the so-called cup cells (Becher-zellen). 



The columnar cells, of which several hundreds are usually 

 seated on each papilla, consist of an ellipsoidal body, 0'006 of 

 a millimeter long, and 0*004 of a millimeter broad, situated in 

 the deepest layer of the epithelium, and immediately sur- 

 mounting the nerve cushion. Towards the periphery, each is 

 prolonged into an ordinary straight columnar process of about 

 0'032 of a millimeter in length, and 0'002 of a millimeter in 

 thickness, which reaches to the external surface of the epithe- 

 lium. The body consists of a thin investment of protoplasm 

 around an ellipsoidal nucleus. The long cylindrical process is 

 composed of very finely granular protoplasm, that appears to 

 be surrounded by a thin membrane open above. The proto- 

 plasm of the cell body is extended usually in the form of a 

 few short processes upon the surface of the nerve cushion. 

 These processes never present the appearance of nerve fibres. 



The columnar cells are no doubt in great part the " rod-cells "'of Key. 

 (See especially figs. 5, 7, 10, 11, b, c, g, of his work.) He associated 

 them, however, with the forked cells to be immediately described 

 of which only mutilated and imperfect examples appear to have fallen 

 under his observation. I conclude that the long process of the 

 columnar cells is enclosed by a membrane open above, from the 

 circumstance that, as for example, in iodine and serum preparations 

 it sometimes gradually flattens and becomes ribbon-like, whilst at the 

 same time small masses of protoplasm protrude from the apex. 



The forked cells (figs. 277 and 278), the number of which is, 

 perhaps, double that of the goblet-cells, consist, like the gus- 

 tatory cells of Mammals, of a body with long thin processes. 

 The body has the form of an elongated ellipsoid, of 0'006 0'008 

 of a millimeter in its longest, and 0*003 0'004 of a millime- 

 ter in its shortest diameter, and is almost entirely filled by 

 a vesicular nucleus with a central nucleolus. The processes 

 spring from the peripheric and central poles of the bodies. 



