290 ON THE CORPUSCULA TACTUS 



possibilities arise — either they may be still the instruments of a 

 modified sense of touch, or they may be merely rudimentary repre- 

 sentatives of the more completely formed organs. At present there 

 appears to be no sufficient evidence to decide this point ; and I would 

 merely wish to draw attention to the fact, that these organs are not 

 isolated structures, but form a series, with the function of whose 

 highest members only, we are at present fully acquainted. 



DESCRIPTION OF PLATE I., Vol. II. [Plate XXIV.] 



Fig. I. Four papillae from the point of the finger ; the largest containing a tactile corpuscle 



with its nerves, while the others possess capillary loops. Acetic acid added — 



a. Nerves, h. Neurilemma, c. "Nuclei." d. Capillaries. 

 Fig. 2. A papilla from the finger of a Tahitian, with a small tactile corpuscle. Letters as 



above. iVcetic acid added. 

 Figs. 3, 4, 5. Termination of nerve-fibres against tactile corpuscles. Caustic soda added. 



■600. 

 Fig. 6. Extremity of one of the papilla at the base of a Frog's tongue, the epithelium being 



stripped off 

 Fig. 7. A nerve, consisting of a single, dark-contoured fibril in its neurilemma, from the 



human finger. 

 Fig. 8. Portion of the wall of a Pacinian body from the human finger. 

 Fig. 9. Section perpendicularly through one of the ridges on the beak of a Duck. /. Horny 



layer of epidermis, in. JIucous layer, n. Derma, p. Pacinian bodies. 

 Fig. TO. A single Pacinian body of the same. 



Diagrams. 



A. Of a Tactile corpuscle. 



B. Of a Pacinian body. 



C. Of a Savian body. 



D. Of the " Muciparous Canals'' of fishes. 



E. Of a Vibrissa of a rat. 



