24 
of locomotion, and for this reason are called antherozoids. These 
antherozoids often drag with them a little vesicle, which seems to play 
no part in the process of reproduction. 
Archigonia, — The archegonium is also a rounded mass of tissue 
usually less prominent than the antheridia, consisting of an external 
layer of cells and a large central cell, which soon divides into two. 
The lower portion, at first the larger, develops into a roundish cell, 
which is analogous to the ovule of flowering plants, and is called the 
oosphere. The upper portion of the central cell develops between 
those composing the neck of the archegonium into a canal filled with 
a sort of mucilage ; this finally swells up, forces the cells of the neck 
apart, and is expelled to aid in attivcting and retaining the authero- 
zoid at the neck of the archegonium. The oosphere is thus left 
exposed. 
Fe7'liUsatio7i. — The antherozoids, analogous to pollen of flowers, 
when discharged from the antheridium, swim in the moisture always 
present on the under surface of the prothallus, swarm in large 
numbers aroung the neck of the archegonium, and are retained by 
the mucilage. Some finally force their way into the canal of the neck, 
a few reaching the oosphere and disappearing within its substance. 
Thus it would seem proved that in ferns there exists a true sexual 
generation. j\fter fertilisation, the neck of the archegonium closes, 
and the fertilised oosphere, now called the oospore^ increases in size, 
and finally develops into a tiue fern. After the oosphere has been 
fertilised, it commences its growth by ordinary processes of cell 
multiplication, and for a time remains within the walls of the 
archegonium, which continue to grow, until finally the interior growth 
breaks through the walls, differentiated into its first root and leaf. 
The young fern draws its nourishment from the prothallus for a time, 
but soon develops root-hairs, which, extending into the soil, maintain 
thereby an existence independent of the prothallus, ^vhich then withers 
away. * Another mode of reproduction from the prothallus is that it 
produces buds, without the formation of sexual organs. 
YEGETAliUF. PuYSIOLO&T. 
As a large number of the terms explained in this work refer to 
that part of botany termed A^egetahle Physiology, it has been thought 
well to give in this place a brief suujmary of the subject. As, 
however, the auihor feels that nothing which lie could write would be 
so terse as Dr. Maxw'^ell T. Master’s chapter upon the subject in his 
“ Botany for Beginners,” free use has been made of it in the present 
instance. 
“The minute structure of plants consists of ceUs, iuhes^ and 
vessels^ of various kinds, disposed in various w’ays. The cells are 
bladders of membrane, of different shapes and sizes arranged in 
diverse methods. Within the outer bladder, or cell-wall as it is 
called, are, at least, in the young active condition, certain contents, of 
which the most important for our present purpose is a mucilaginous 
fluid, called froioplasin. All cells, except those which are old, contain 
more or less of this protoplasm, which is the most important part of the 
cell so far as functions are conceimed. The bladder, orcelI-wall,isnjerely 
a kind of protecting skin, composed of cellulose^ a substance akin to 
starch. Within the cells are formed or deposited various substances, 
