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bacteria dishes containing a few centimeters of mud covered with 3 
to 5 cm of water. The average length of the worm is from 4 to 
7 cm. The worm forms in the mud a flexible tube open at both 
ends, composed chiefly of particles of the soil cemented together by 
the mucus of the skin. While contracted, the body lies wholly within 
this tube. When unmolested, the posterior one-third to one-half of the 
body extends from the tube into the water, where it waves about in 
a rapid undulatory manner, while from the other end of the tube is 
protruded the anterior end of the worm, which is thrust about through 
the mud in search of food. 
Methods. 
For general epidermal histology, narcotization with 5°/, alcohol, 
and killing in 100°/, alcohol gave excellent results. 
The Enruicu-Bionpt triple stain, and Haematoxylin of DELAFIELD’s 
and KLEINENBERG’s formulae were largely used. The cuticle was isolated 
from the other tissues by careful maceration of portions of the body 
wall in dilute Kuskow’s fluid. 
Of nerve methods, the rapid GoLGI process gave the best results. 
Unnarcotized worms were killed in a solution composed of 3,5 °/, 
Potass. Bichromat, eight parts; 1°/, Osmic Acid, one part. After 
70 hours they were transferred to 1°/, Silver Nitrate and left 45 to 
50 hours. vom RarH’s method with Pyroligneous Acid gave good 
results. Methylen Blue proved nearly useless. 
Descriptive. 
The cuticle is a thin dense layer 1,5 « to 2 win thickness. When 
isolated, openings or markings of two sorts are visible. These are 
probably the pore canals from the gland cells and the openings 
occupied in the living condition by the hairs from the sense cells. 
No striations upon the surface of the cuticle have been made out. 
The cellular layer of the epidermis contains cells of three well 
marked types, vic: gland cells, supporting cells and sense 
cells. 
The posterior extremity of the worm is in a highly vascular 
condition. At a distance of about 4 millimeters from the end, the 
body wall merges into a mass of cells lying against the great dorsal 
blood vessel and constituting the growing zone; anterior to this, the 
body wall is marked off into its distinct layers. In the growing zone 
the epidermis consists of the following elements: 1) columnar cells, 
extending thro the layer from cuticle to base, with large lightly stained 
