440 



INNERVATION. 



[CHAP. 



rally inclined backwards. These epithelial processes are more stiff, 

 according as the particles of which they consist approach more 

 nearly to the dense texture of hair; and a few among them 

 actually enclose minute hairs, pointed at the end, and provided 

 in some cases with an extremely fine central canal. One of the 

 largest of these we found ^ of an inch long, and from T -^-o to 

 3 oVo f an i ncn ^ick (fig. 100, 2). The others have an imbricated 

 arrangement of the particles in various degrees, which will be un- 

 derstood without detailed description on reference to figure 100, 3, 

 4, 5. Many of them may be regarded as soft or uncondensed hairs, 

 and preserve the same thickness for a considerable length. 



The structure of the secondary papillae, from which these hair-like 

 processes pass off, differs somewhat from that of the simple papillae 

 in the situations previously described. This difference consists in their 

 larger size and more pointed form, as well as in their greater stiffness 



Fig. 101. 



A. Secondary papilla of the conical class, treated with acetic acid :a. Its basement membrane. 

 b. Its nerve-tube forming a loop. c. Its curly elastic tissue. The epithelium in this instance is not 

 abundant ; but the vertical arrangement of its particles over the apex of the papilla is well seen, <f, 

 and illustrates the mode of formation of the hair-like processes described in the text Mag. 160 

 diameters. 



B. A similar papilla, deprived of its epithelium : . Basement membrane. 6. Tubular fibre, pro- 

 bably forming a loop, but its arch not clearly seen, c, c. Elastic fibrous tissue at its base and in its 

 interior. Magnified 320 diameters. 



c. Nerves of a compound papilla near the point of the tongue, in which their loop-like arrangement 

 is distinctly seen. Magnified 160 diameters. 



