8 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



tongue run into papillae, of which the to-called circumvallate, on 

 the posterior part of the tongue's surface have an especially rich 

 nerve supply. On these are the terminal organs of taste con- 

 sisting of peculiar bodies, the so-called taste-bulbs or taste-buds, 

 discovered by Schwalbe and Loven in 1867. These taste-bulbs, 

 which are minute bodies, oval in shape, are lodged in the epi- 

 thelium covering the side of the papilla. Each consists of two 

 sets of cells. On the outside are a number of flat, fusiform, nu- 

 cleated cells known as supporting or protective cells; these are 

 bent like the staves of a barrel and arranged side by side so as 

 to form a bulb-shaped body, having an aperture at the apex 

 known as the gustatory pore. The inside of the taste-bulb con- 

 tains five to ten so-called taste-cells, which are pointed at the end 

 next to the gustatory pore and branched at the other end where 

 they are probably connected with nerve fibres. According to 

 Eanvier 1 supporting cells are also found in the interior of the 

 taste-bulbs, the taste-cells being found interspersed between 

 these. Taste-bulbs occur also on other papillae of the tongue, 

 and it is possible that simpler structures consisting of fewer or 

 even single taste-cells exist where no taste-bulbs are located, for 

 it is known that taste does exist on parts of the tongue where no 

 taste-bulbs have been found. The tip, edges, and back of the 

 tongue are sensitive to taste, while the middle is devoid of 

 taste. The organs of taste are similar in construction to those 

 of smell. 



The above is a brief statement of what is generally given con- 

 cerning the organs of taste in standard works 2 on physiology, 

 histology, and physiological psychology. Ketzius, 3 who has 

 made an, extensive study of the nerve endings of the various or- 

 gans of the special senses, states that he has been unable to find 

 nerve-fibres connecting the so-called taste-cells with the nerve 

 underneath, that the lower terminus of the taste-cells is in many 



iTraitg Technique d'Histologie, p. 946. 



2 See for example Martin, The Human Body; Ranvier, Traits d Histologic; 

 Wundt, Grundztige der physiologischen Psychologie. 

 3 Biologische Untersuchungen IV., p. 24. 



