114 SMELL, TASTE, ALLIED SENSES 



tongue a V-shaped row whose angle points toward the 

 esophagus (See Fig. 25). Each papilla is a low circu- 

 lar elevation surrounded by a relatively deep, narrow 

 ditch. The taste-buds are located on the walls of this 

 ditch and chiefly on that wall which forms part of the 

 papilla. In a vertical section through a vallate papilla, 

 it is usual to see on the side of the ditch formed by the 



Fig. 27. — Vertical section of a vallate papilla showing taate-buds. 



papilla from ten to a dozen taste-buds and on the side 

 away from that structure four to six such bodies 

 (Fig. 27). However, as Schwalbe (1868) long ago 

 pointed out, much individual variation occurs and it is, 

 therefore, very difficult even to estimate with any degree 

 of accuracy the total number of taste-buds on a single 

 papilla. W. Krause (1876) believed the number for a 

 single papilla in man to be as high as 2500, but von Wyss 

 (1870) placed it much lower, namely, at about 400. Even 

 these figures seemed too high to Graberg (1899) who gave 

 the maximum at 100 to 150 and the minimum at 40 to 50. 

 Heiderich (1906) made a close count on 92 papillae from 

 human beings ranging in age from the first to the twen- 

 tieth year and found the extreme numbers of buds to a 



