NERVE TERMINATIONS OF THE TADPOLE. 55 
with each other to form a second plexus. The finest fibrils are 
described as occurring immediately underneath the epithelium 
in a network, the meshes of which are so narrow that several 
of them can be covered by the nucleus of an epithelial cell. 
As no nerve-fibrils could be traced beyond this network, Klein 
concluded that they terminate in it. 
Lebouncq! also found a terminal sub-epithelial network in the 
skin of the larve of Pelobates and Triton, its meshes, how- 
ever, not being so narrow as those of the network described by 
Klein. He observed, also, nerve-fibrils terminating in homo- 
geneous finely-granuled corpuscles situated among the epithelial 
cells, and provided with processes which end in the intercellular 
substance. Leboucq compared these corpuscles to the cells of 
Langerhans in the Malpighian layer of the human skin, which 
acquire a violet tint when treated with gold chloride, and which 
are considered by some observers to be the end-organs of intra- 
epithelial nerve-fibrils. He believed that some of the fibres 
terminate in the nuclei of the cells described by Leydig under 
the name of “ Schleimzellen.” 
Pfitzner’s work,” next in the order of time, deals specially 
with the intra-epithelial terminations of nerves. This observer, 
by first hardening the tissue with chromic acid, then treating 
the separate sections with gold chloride, found that the figures 
of Eberth attained in every case a violet tint, and he considered 
them consequently to be nerve terminations. He also, by the 
employment of saffranine, as well as by the use of gold chloride, 
observed that these structures are continued through the corium 
into the subcutaneous tissue. According to Pfitzner every 
epithelial cell has two figures of Eberth in its interior, which 
terminate in knob-like swellings near to, but never touching, 
the nucleus. 
Now, in the plate accompanying Pfitzner’s work there is 
apparently no resemblance between the figures of Eberth, as 
one usually sees them, and the nerve endings there repre- 
sented. Canini,® who followed Pfitzner’s methods of research, 
1 «Bulletins de l’Academie Royale de Belgique,’ 1876, p. 561. 
2 *Morph. Jahrbuch,’ Bd. vii, p. 726. 
§ * Arch. fiir Anat. und Phys.,’ Phys. Abth., 1883, p. 149. 
