149 
of Water in Mosses. 
of the Moss. I chose Polytrichum commune for my ob- 
servations as before, with the results given below stated for 
the stem ; as the leaves gave the same results, these are 
not mentioned separately. 
Transverse sections of stem of oophyte : — 
Iodized zinc-chloride ( Schulze's solution ) : — central strand 
of small-celled tissue only coloured blue, all the external 
tissues coloured yellow . 
Caustic potash : — the cell-walls of the peripheral tissue 
remain brown and are not dissolved by boiling. 
Aniline chloride : — the cell-walls of peripheral sterome 
lose their brown colour and become yellow. 
Chromic acid , strong, but not quite concentrated : — rapidly 
dissolves all the cell-walls without leaving anything whatsoever 
except the protoplasmic contents of the cells which float 
about freely in the liquid ; there is no trace of a cuticle to 
be found either on the leaves or stem. 
Nitric acid and chlorate of potash (Schulze s mixttire ') : — 
sections warmed in this mixture become completely colour- 
less, and all the cell-walls give characteristic cellulose-reaction 
with iodized zinc-chloride, even the most external layer of 
all. 
Nitric acid : — turns all the cell-walls of external tissues 
and those of the central strand orange yellow. 
Hydrochloric acid : — turns cell-walls of peripheral tissues 
from yellow-brown to orange or red-brown, with purplish 
tint in some of the more external cell-walls. 
Sulphuric acid , strong : — causes swelling more or less of 
cell-walls of all the tissues. 
Carbolic acid : — turns peripheral tissues a very slight 
greenish tint. 
In view of the ease with which water is absorbed at the 
surface of the leaves and stem of the oophyte of this Moss 
at least, and of the actions of the re-agents given above, 
it will, I think, be clear that there is no cuticularization of 
the cell-walls nor is there any cuticle present. From the 
action of some of the re-agents it is evident that the 
