( 453 ) 



The structure of the peculiar organ first described by Eimer (1870) 

 and the innervation of it, have been studied in the course of this 

 year (1907) by two authors ^) by means of the recent improved methods 

 of staining the neurofibrillae. Both give about the same description 

 but arrive at different conclusions. 



As is well known, the organ of Eimer consists of thickenings of 

 the epidermis, formed by columns of epithelial cells in the shape of 

 an hourglass, which form small round prominences on the surface 

 of the snout, and which, because the columns of cells are longer 

 than the thickness of the epidermis at the place where they are 

 found, project with their base into the corium, and form here a 

 bulging out of the epithelium, generally described as "buffershaped". 

 Each of the columns is made up of several strata of more or less 

 flattened epithelial cells, which at the base of the column do not 

 reach from one side to the other, but are wedgeshaped and over- 

 lapping each other with the thinned-out ends. Nearer the surface 

 the cells gradually become flattened and larger, until only two cells 

 lying at the same niveau, fill out the entire cross-section of the 

 senary column (fig. 1, 5). There the column ends as it reaches the 

 horny layer. The cells of the column are, according' to Botezat, true 

 spiny cells like the other cells of the epidermis (fig. 3). 



In the axis of the column a thick nerve fibre, the axial fibre, 

 runs through the whole length of it, penetrating into the epithelium 

 at its base. Sometimes there are two or three axial fibres. Around 

 the column of cells a set of 18 or 19 thin, unbranched nerve fibres, 

 closely set, somewhat zigzag, run upwards between the outer ends 

 of the cells of the column and the adjoining epidermis-cells, until 

 they reach the horny layer. These are called rand-fibres to distinguish 

 them from the axial fibre, At the base of the column between the 

 epidermis-cells a small number of tactile cells of Merkel are found, 

 and underneath the epidermis in the corium one or two small 

 Pacinian corpuscles. 



Eimer already described small varicosities or knoblike swellings of 

 the nerve-fibres in the upper part of the columns. The nerve-fibres 

 run more or less zigzag between the cells. Eimer himself and after 

 him Huss (1898) thought that these knoblike varicosities were lying 

 intracellular, the nerve-fibres running between the cells. The vari- 

 cosities are therefore attached laterally to the nerve-fibres. 



1) EuGEN Botezat. Anal. Anzeiger, 30 Bd. 1907. 



M. BiELSCHOwsKY. Anat. Anzeiger, 31 Bd. 1907. 



31* 



