Notes. 
407 
quite distinctly articulated (cf. Fig. 22, 7), are treated with chlor-zinc- 
iodide, we find that, whereas the external wall of the hair takes on 
a distinct violet tinge, the transverse portions round themselves off, 
becoming slightly yellow. Congo-red stains the walls of the cells 
a light ted colour ; the walls of the hairs take on a similar, but much 
fainter tinge, and no transverse portions in the course of the hair are 
stained, thus proving that there are no transverse cellulose-walls. 
The false septa show up well in the stained hair, but do not seem 
to take on any colour themselves. They are seen to be small, highly 
refracting bodies of various size and shape, and at high focus appear 
to have a slight yellow tinge. 
The first indication of a developing hair is to be seen when the cell 
elongates slightly in the direction of the future hair. At the same 
time the (somewhat bluntly) pointed apex of the cell becomes colour- 
less (Fig. 22, 5), the green contents collecting in the hinder part of 
the cell. The colourless tip is full of protoplasm, which no doubt 
plays an important part in the elongation of the hair, which now takes 
place (Fig. 22, 6). I was not able to observe the division of a nucleus 
and the transfer of the one half into the young hair, as described by 
Huber 1 for Aphanochaete repens, Braun. After the first rudiment of 
the hair is formed, elongation goes on more and more rapidly, and 
the growing colourless apex becomes more slender. When the hair 
has reached from 2-3 times the length of the cell, the bulbous base 
commences to form, and the hair is cut off by a thin transverse wall 
from the cell below it; this wall may be formed sooner or later in 
different cases, however. Before the formation of this wall the 
protoplasm extends irregularly into the hair for some little way, but 
afterwards only a Small quantity remains in the young hair. This 
is chiefly aggregated at its apex; which at this stage has the appear- 
ance of being quite solid ; there is only a distinct lumen in the bulbous 
base. When this base is once formedj elongation proceeds very 
rapidly, and at the end of about twenty-four hours the hair is 6-10 
times as long as the cell it has developed from 2 (Fig. 22, 7). During 
this later elongation the protoplasm, which was before aggregated in 
the apex, becomes split up into a number of separate portions, some 
1 Loc. cit., p. 326, Fig. 2 a , and b. 
2 It will be Observed, that this account does not agree in all respects with 
Huber’s ; we have, however, undotibtedly examined different species, and the 
differences are not very important; 
