40 Journal of omparative Neurology. 



Our own studies of the gustatory epithelium of the axo- 

 lotle are in accord with the results of Bethe upon the frog so far 

 as the diffuse endings are concerned, though the methylene blue 

 does not give adequate insight into the connections between 

 fibers and cells. The taste buds, on the other hand, afford sim- 

 ilar results to those obtained from the sensory buds of the skin. 

 The source of many of the erroneous conclusions reached is, as 

 mentioned beyond, the fact that in successful methylene blue 

 preparations it often happens that fibrous elements stain when 

 the cells of origin for the same fibers do not. 



Diffuse Pei'ipJieral Connections. — Various early writers have 

 reported the existence of a dense net-work or felting of nervous 

 material among the epithelial and even the corneum cells of the 

 skin. This structure was first made out by the use of gold 

 chloride and there was always left open the possibility that the 

 appearance was due to the disposition of metallic salts in the 

 interstices between the cells. Dogiel in his paper on the nerve 

 endings of the genitalia figures a very extensive mesh-work of 

 this kind with here and there a free knob-like termination and 

 he traces the lower part of the reticulum to a direct communi- 

 cation with a set of nerve fibers passing perpendicular to the 

 skin. (Fig. i.) Strong in his paper on the cranial nerves of 

 the frog figures a similarly minute meshwork which is revealed 

 in this case by the use of the Golgi method. In all of the above 

 cases there is the element of uncertainty growing out of the 

 fact that the methods are impregnation rather than staining pro- 

 cesses and are histologically uncertain. It would then be emi- 

 nently desirable to supplement the evidence from these sources 

 by other means. In the study of the skin of the Amphibia it 

 is easily noted that there exists at the base or ental aspect of 

 the layer of Malpighi a layer or stratum which is in a peculiarly 

 nascent state. These cells are devoid of the thick and risfid 

 walls chatacteristic of the superficial cells and are protoblasts 

 rather than complete cells. In this layer we may find, at all 

 stages, the evidences of mitotic division. In fact there is a per- 

 manent proliferating zone in this region. Comparison of this 

 stratum with that of higher vertebrates shows that the latter form 



