146 Journal of Comparative Neurology. 



tion but in a relatively large number of them. I have felt, how- 

 ever, that especially figures drawn from Golgi preparations are 

 apt to give a wrong impression, since such figures are usually 

 drawn from sections of tissues so stained and can, as must be 

 obvious on a moment's reflection, give only a portion of the 

 entire ending, at most only here and there a portion of one or 

 several arborizations, and these usually not in connection with 

 the larger nerve branches. 



That many of the terminal branches of the arborizations 

 here mentioned end in the epithelium it seems to me can not 

 be questioned. Arnstein (11) and the writer (12) have shown 

 nerve fibers in the epithelium of the salivary ducts ; Ploschko 



(13) in the epithehum of the trachea and epiglottis ; Berkley 



(14) in the smaller bronchi; Smirnow and Retzius (23) in the 

 oesophagus (this Dr. DeWitt has corroborated as will be pub- 

 lished later); Retzius (24) has described nerve fibers in the epi- 

 thelium of the bladder and Griinstein (21) finds intra-epithelial 

 pericullular nerve endings in the bladder of the cat, although in 

 the dog, if I read him correctly, he speaks of finding only 

 " intermusculare Endapparate. " 



I have observed intra-epithelial nerve fibers in numerous 

 preparations stained in methylen blue in which I was able to 

 trace some of the terminal branches of arborizations, such as 

 above mentioned, into the epithelium. Such observations, I 

 may say, are most satisfactory if made on unfixed tissue, which 

 after injection with methylen blue and after removal from the 

 animal, is examined at a time when the nerve fibers have reached 

 their maximal stain. The purplish-blue, terminal fibers may 

 often be clearly seen between the epithelial cells, which are 

 either only faintly stained, or if stained have a more greenish 

 blue color. In methylen blue preparations fixed in ammonium 

 picrate the epithelium is usually somewhat macerated, so that 

 on mounting the preparation much of the epithelium is lost. 

 Usually, however, some patches remain in which terminal 

 branches of nerve fibers may be found, it must be confessed 

 not so clearly as in unfixed specimens. Of the methylen blue 

 preparations which I have made and examined more recently 



