46 Journal of Comparative Neurology. 



each cell bears a slight conical enlargement whose base forms 

 part of the surface of the organ. There seems to be no hair 

 or other projection. The nerve fibers supplying the organ come 

 up through the thickened subcutaneous tissue and lose their 

 medullation as they pass through the dermis. Up to this point 

 they have the caliber of lateral line fibers and in Golgi sections 

 they appear thicker than the general cutaneous fibers. Surface 

 precipitates have prevented the full study of these organs by 

 the Golgi method, but the branching of the nerve fibers about 

 the bases of the sense cells was seen. 



The second set of sense organs are the end-buds (Fig. 27). 

 These organs do not produce a thickening or other externally 

 noticeable mark in the epidermis, and in sections are to be 

 made out only by the arrangement of their cells and the slightly 

 deeper stain which these cells take. The end-buds are shaped 

 like a goblet or wine glass from which the base is broken off. 

 The body of the organ stands in the outer layer of the epi- 

 dermis and the stem penetrates the inner layer. The stem con- 

 sists largely of the nerve fibers which supply the organ. The 

 organ consists of sensory and supporting cells. The supporting 

 cells are cubical or rounded, have not the vacuolated appearance 

 of the cells in the outer layer of the epidermis, take a deeper 

 stain and are closely packed into a dense mass. Among the 

 supporting cells are slender spindle-shaped cells with elongated 

 nuclei which take a black stain. The cells are exceedingly slender 

 and have the appearance of thick sinuous fibers. The outer 

 end reaches the cuticula and the inner end, in some cases at least, 

 reaches the inner border of the epidermis. In iron haematox- 

 ylin sections fine nerve fibers which stain an intense and char- 

 acteristic blue are seen passing through the dermis and up along 

 side of the sense cells. Similar fibers are seen in Golgi sections 

 although the sense cells are not impregnated. 



The number and distribution of these organs over the 

 whole head could be worked out from sections. A brief exam- 

 ination of sections indicates that there is probably no regularity 

 in their distribution, although in the gill region there are more 

 near the mid-dorsal and ventral lines than elsewhere. The total 



