484 
Notes. 
a single superficial cell. This divides transversely, the outer half 
giving rise to the outer antheridial wall and the inner half by repeated 
simultaneous divisions to a large number of spermatocytes. The fully 
developed antheridium is largely embedded in the antheridial ridge, 
and projects only slightly above its surface. The formation of the 
spermatozoids has not yet been carefully studied, but seems to 
resemble closely that described in the Marattiaceae and Equisetaceae. 
The spermatozoids are usually large in size, but otherwise resemble 
the ordinary Fern-type, and consequently differ from the biciliate 
Moss-like spermatozoids of the Lycopodiales. 
The archegonia are confined to the sloping sides of the upper 
surface of the prothallium. Unlike the antheridia, young archegonia, 
although most abundant near the growing-point, may be formed on 
almost any part of the archegonia-bearing surface. The mother-cell 
of the archegonium is superficial, and is distinguished from its neigh- 
bours by a large nucleus and a more abundant protoplasm. It first 
divides transversely into a shallow outer cell and a deeper inner cell. 
The inner cell divides again, and as a result the young archegonium 
consists of three cells. The most external of these, by subsequent 
divisions, give rise to the neck of the archegonium. The internal 
cell is the basal cell. It also divides into a plate of cells, some- 
times composed of two layers, distinguished by their richly proto- 
plasmic contents. The middle cell of the young archegonium-series 
gives rise by division to the neck-canal-cell and to the ventral cell. 
The former becomes binucleate, but never divides into two cells. The 
latter, just before the maturation of the archegonium, divides into 
the egg-cell and the ventral canal-cell. The ventral canal-cell is 
broad, like that of the Marattiaceae. 
In the ripe archegonium, the nuclei of the cells of the upper stories 
of the archegonium-neck become chromatolysed. I do not know yet 
whether this feature is peculiar to Botrychium. 
The fully-developed archegonium is sunk into the prothallium, 
and only the neck projects above its surface. The cervical cells 
are in four rows as in the other Pteridophyta, and the terminal ones 
spring apart when the egg is ripe. 
Spermatozoids are frequently found in contact with the egg. After 
fertilization the egg grows to many times its original size, and the 
reduced protoplasm contains a large hydroplastid. 
The first division of the oospore is across the long axis of the 
