256 PAPILLA OF FROG'S TONGUE. 



ment as I have given it is correct. In my specimens the 

 fine nerve fibres traversing the muscular fibres can be seen 

 very distinctly. The bioplasts of these often come very 

 close to the muscular tissue, but they are not embedded in 

 it. The bioplasts of nerves, muscles, and vessels are very 

 distinctly seen in this specimen. These tissues have all 

 been developed part passu, each texture being formed by 

 its own proper bioplasm. 



Although the bioplasts of the several tissues are very 

 near to one another, they never interfere with each other's 

 growth, or coalesce. The complex changes proceed in a 

 perfectly orderly manner from the first, and if nothing inter- 

 feres with the several changes as they succeed one another 

 with perfect regularity, the formation of the several tissues 

 constituting the highly elaborate apparatus delineated, will 

 be complete, and the arrangements by which it is brought 

 under the control of the animal's will, perfected. 



Papilla of Fro^s Tongue. In such an organ as that 

 represented in PL XV, the relation of a number of different 

 textures, performing very different and distinct offices, is 

 beautifully shown. In this minute papilla less than the T^th 

 of an inch in height, we find epithelium, connective tissue, 

 muscular fibres, capillary vessels, and three classes of nerve 

 fibres ; i. Those concerned in special sense. 2. Motor nerve 

 fibres; and 3. Nerve fibres distributed to the capillaries. 

 These different textures have all grown together, and, 

 although placed close together, they do not in any way 

 interfere with one another's action. I know of no tissue in 

 which the relation of the peripheral ramifications of the 

 nerves to other tissues can be studied with such success as 

 in these papillae. 



