i6o 
Notes . 
began with the rise of one or two of the apical wall-cells. Then the remaining cells 
drew back with little jerks, presenting the appearance of the loosening of a claw of 
filaments. At the same time a stream of antherozoids appeared, which was helped 
out of the antheridium by the pushes given by individual cells jumping-off, and by 
filaments of wall-cells rising and drawing back. The appearance was very striking, 
and the discharge occupied about two minutes. The individual cells of the wall were 
turgid sausage-shaped bodies. After the rejection of the antherozoids, what remained 
of the cell-filaments could be seen attached to the rim of lower cells which acted as 
a kind of stalk. 
The antheridia of Haplomitrium Hookeri are oval bodies, and are much larger 
than the more or less spherical ones of Fossombronia. When ripe, these are of an 
orange colour, due to a similar change in the chlorophyll corpuscles of the wall, which 
are roundish in outline. The wall of the antheridium lacks the differentiation seen in 
Fossombronia. The cells are five- or six-angled, and are arranged in a diamond 
pattern. As the antheridium ripens first, the apical cells, and later the lower cells, bulge 
outward, giving it a warty appearance, which is not so marked towards the base. In 
nature the discharge of antherozoids is sudden and rapid. In attempting to examine 
the process, dehiscence is often premature, and the discharge less rapid. In one case 
the contents passed out in a cloud, which became several times longer than the antheri- 
dium during a couple of sudden movements which resulted in the complete collapse 
of the spirally-arranged, turgid wall-cells. These remained attached to the basal 
portion of the antheridium. 
In another case where the process was retarded, an orifice was formed at the 
apex, owing to the uprising of a few turgid cells. Previous to this the radial walls of 
the apical cells appeared thick and discoloured, due to the arrangement of a yellowish- 
brown mucilaginous matter about their walls. The free cells, bounded by a thin, 
clear membrane, soon lost their turgidity, and the orange or orange-brown coloured 
matter diffused from the changed chlorophyll corpuscles into the protoplasm. After 
the formation of an orifice, more and more cells rose, but did not float off, and the 
antherozoids oozed out. The wall of the antheridium bulged in places, and it could 
be seen that the membrane of the sausage-shaped cells was free from the limiting 
membrane (cuticle) of the wall. 
To sum up, the following processes take place during ripening of the 
antheridium : — 
1. Change in character of the chlorophyll corpuscles of the wall from above 
downwards. 
2. Local degeneration of the middle lamella in the wall of the antheridium. Cell 
filaments are formed in Fossombronia. Special cells rise in Haplomitrium. 
3. The upper wall-cells become free from the limiting membrane of the wall. 
When these processes have operated for a certain time — that is to say, when the 
antheridia are ripe — dehiscence takes place, and, since the wall-cells are normally in 
a turgid state, the mere access of water would be sufficient to start dehiscence. The 
disposition and behaviour of the wall-cells in each case provide a simple and efficient 
mechanism for the discharge of antherozoids. 
A. S. HORNE. 
Armstrong College, Newcastle-upon-Tyne. 
