GUSTATORY ORGANS OF THE FISH. 21 



cup-shaped organs (bcckerformigen Oryane). They are bulbous 

 structures, composed of peculiar cells, situated in the laminated 

 epithelium of the skin and oral mucous membrane. At many 

 points, cylindrical papillae, containing nerves, project from the 

 connective tissue lying subjacent to the cutis, or mucous 

 membrane, into the epithelium, and a cup-shaped organ occu- 

 pies the somewhat excavated summit of each. 



Leydig, who discovered the structures in question in the external 

 skin of fresh- water fishes, w 7 as inclined to regard them as tactile 

 organs. F. E. Schulze has since clearly demonstrated them to be 

 gustatory organs. He found that they were present in those portions 

 of the palatine mucous membrane of the Fish, supplied by the glosso- 

 pharyngeal nerve, and investigated their structure more minutely, 

 discovering their close analogy with the gustatory apparatus of 

 the Frog. The whole system of cup-shaped organs appears, according 

 to Schulze, to be most developed in the cyprinoid fishes. The 

 organs in question are here very closely placed in the palate, in the 

 rudiment of the tongue, and on the mucous membrane covering 

 the inner side of the bronchial arches, as also on the beard. They 

 are somewhat farther apart on the lips, still farther on the skin of the 

 head and of the rest of the body. They have not been observed on 

 the lips of Cottus gobio nor in the external skin of the Pike, Salmon, 

 Torsk, or Herring. 



Each cup-shaped organ consists of a fasciculus of very, long 

 closely compressed cells that reach from the cutis or from the 

 papillae of the mucous membrane to the free surface of the 

 epithelium. The length of these cells may be O'l of a milli- 

 meter or more. According to F. E. Schulze, two different 

 types of cells may be distinguished in each cup. One of these 

 corresponds to the investing cells of the gustatory bulbs of 

 Mammals, and to the goblet and columnar cells of the gustatory 

 disks of the Frog, and are chiefly situated in the peripheric 

 part of the organ. They are long cylindrical cells obliquely 

 truncated at their upper extremity, with their nucleus, 

 which contains nucleoli, situated near their centre. Towards 

 their inferior extremity, the cells, after becoming slightly 

 attenuated, run out into a few slender finger-like or angular 

 processes. 



