194 Bews—A CAVITY FILLED WITH HAIRS IN 
Appearance of the Hair-Cavity (Figs. 1 and 3). 
This cavity differs entirely from the original central hollow. 
It is bounded by a very regular layer of cells, which differ greatly 
in appearance from the other cells of the pith, being much 
smaller, and having thicker walls and abundant cell-content. In 
fact, they are extremely like the ordinary cells of the epidermis. 
Two or three rows of cells next to this layer also differ from 
the cells of the pith in being smaller and having plenty of cell- 
content. Not only, therefore, does this hair-cavity have a 
distinct origin apart from the original central cavity, but the 
cells surrounding the two cavities also differ. 
Appearance of the Hairs (Figs. 1, 2, and 3). 
From the surrounding layer of cells hairs project outwards 
into the cavity. These hairs are of two kinds—pluricellulur and 
glandular. ; 
The former are the more numerous. They are hairs of the 
kind which De Bary describes as “ Conical Multicellulur Hairs”* 
The foot-cell differs slightly in appearance from the others. 
There may be as many as eight or nine cells in a hair, though in 
most of them there are not quite so many. All the cells are full 
of protoplasm (Fig. 1). 
The glandular hairs are not nearly so numerous. They are 
similar to those which De Bary calls “Capitate glandular hairs,” 
7.é., the free end is swollen to form a round head, the transverse 
section of which exceeds that of the stalk. 
The stalk is short, 1-3 celled (Fig 2). 
In one part of the stem which I examined, in addition to the 
main hair-cavity, a very much smaller one appeared close to it. 
This smaller hair-cavity was also filled with hairs of both kinds. 
Before discussing the possible significance of this structure, I 
may here explain that the material which I first examined was 
among that which had been supplied from the Edinburgh Royal 
Botanic Garden for the use of students in the Winter Class of 
Botany. It consisted of short pieces of the stem of several 
Cucurbits. I was able to find three or four short pieces, probably 
*De Bary. Comparative Anatomy of Phanerogams and Ferns, pp. 59-61. 
