ANATOMY OF THE GUSTATORY ORGAN 123 



the buds are as intimately applied to the so-called sup- 

 porting cells as to the taste-cells, showing, as has al- 

 ready been stated, that the distinction between what 

 has been assumed to be two classes of cells is probably 

 quite erroneous. 



In addition to intergemmal and iperigemmal fibers, 

 which in consequence of their close relations with the 

 taste-buds may be designated as gemmal or bulbar fibers, 

 there are also fibers that pass into the undifferentiated 

 epithelium between the buds and end close to the external 

 surface as free-nerve terminations. These have been 

 called intergemmal fibers, but it is doubtful whether 

 they have anything to do with taste and it is not improb- 

 able that they are concerned with other sensory functions 

 such as the common chemical sense, pain, and the like, in 

 which case a designation implying relations to a taste-bud 

 is in no sense appropriate. 



Taste-buds such as have already been described have 

 been found in a wide range of vertebrates. They 

 not only occur in mammals, where their relation with 

 the nerve-fibers was first correctly described by Retzius 

 ( 1892a) , but also in fishes as seen by Retzius ( 1892a, 1893 ) , 

 vonLenhossek (1893a),Dogiel (1897) and others (Fig. 33). 

 It is, therefore, probable that so far as essentials are con- 

 cerned the innervation of the taste-buds of all vertebrates 

 presents a relatively uniform plan. 



7. Gustatory Nerves. There are no separate gusta- 

 tory nerves in the vertebrates as there are olfactory nerves 

 or optic nerves. Gustatory fibers occur in several crani- 

 al nerves and it is by means of these that the taste-buds 

 of various regions are provided with those nervous con- 

 nections that have been described in the preceding section. 



