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



from the apex of the bulb. The central process is filiform and some- 

 times varicose. Schwalbe was unable to satisfy himself of the existence 

 of the lateral branches described by Loven. In the "rod cells " the 

 peripheric process is " shorter, of uniform breadth, and truncated (?) 

 anteriorly " without the pin or pencil-like point. The central process, 

 on the other hand, is scarcely to be distinguished from that of the 

 ordinary gustatory cells. Whether in various regions of the tongue 

 different forms of gustatory cells are present, which are to be regarded 

 as the conductors of various gustatory impressions, is still unknown ; 

 and in like manner we are still ignorant whether one or several kinds 

 of gustatory cells exist in each gustatory bulb. 



THE NERVES. We are still very imperfectly acquainted with 

 the relations of the nerve fibres to the elements of the gustatory 

 bulbs. We know, however, that branches of the glossopha- 

 ryngeus, which chiefly consist of fine medullated fibres, are dis- 

 tributed to the papillae circumvallatse, and break up in their 

 interior. Shortly before their entrance into the papillae, these 

 branches, like the trunk of the glossophaiyngeus (Remak) 

 contain small microscopic groups of ganglion cells ; immediately 

 beneath the papillae they form a plexus which is particularly 

 well developed in the Sheep (Schwalbe). Proceeding from 

 this plexus, one or more large fasciculi run up in the axis of the 

 papilla, whilst in many instances a few also penetrate its lateral 

 surface, and then break up into numerous fine and frequently 

 decussating sinuous branches which stream out towards the 

 epithelium. As a general rule, these branches contain many 

 more pale than dark-bordered fibres. The greater number of 

 the fasciculi are usually distributed in the vicinity of the gus- 

 tatory bulbs, and these expand into a thin stratum containing 

 numerous nuclei, on which the gustatory bulbs are directly 

 seated. According to Schwalbe, the nerves in this stratum 

 consist, independently of the isolated medullated fibres, of fine 

 fasciculi of fibrils, each of which is invested by a nucleated 

 sheath, which is rendered pale and transparent by acetic acid. 

 These fasciculi undergo continuous subdivision into smaller 

 branches, from which at length fine pale fibres are given off, 

 that closely resemble the processes of the gustatory cells, and 

 form a plexus close beneath the epithelium. It is extremely 

 probable that these finest fibrils are continuous with the central 



