CANADIAN PILIClNEiE. 171 



water, and the antherozoids escaping, are, by the movement of their ciliiu, brought in 

 contact with the archegonia, through the neck of which they make their way to the 

 oosphère and fertilize it, when, immediately beginning to grow, it gives origin to a very 

 small and simple plant. This young plant at first derives its nourishment from the other 

 cells of the prothallium, which, however, soon withers away, its nursling having esta- 

 blished roots of its own. Steadily onward, now, goes the process of development, till at 

 length the young plant begins to assume a likeness to the parent fern. But, having 

 reached this stage, we are still very far from having a perfect plant, for the growth of the 

 fronds is slow, much more so than that of the leaves of flowering plants, and in the great 

 majority of ferns it is generally two or three years before the development is completed. 

 When at length this is accomplished, and the frond is ready to produce fruit, there arise 

 on it (in set places, according to the species of fern) clusters of little, projecting cells. 

 Each of these cells becomes divided into two, one of which either shrivels up and forms 

 a stalk connecting the remaining one with the frond, or entirely withers away ; while the 

 second is divided into five cells, four of which surround the fifth. Each of these four is 

 again divided into two, forming an outer and an inner layer of cells. The outer layer 

 next unites to form a case (sporangium), while the inner disappears, its place being taken 

 by a fluid in which the fifth cell is left floating. This floating cell continues to grow for 

 a time, when it breaks up into a mass of dust-like bodies, — the new spores. Finally, when 

 the fri^it is fully matured, the sporangium splitting, the spores are scattered, and, floating 

 about, at last come to rest in some favourable spot, where they may again begin a fresh 

 cycle of life, such as has just been described. 



The following Synopsis of Genera is taken from Professor Eaton's " Ferns of North 

 America " without change, except as regards its limitation to Canadian species, and the 

 transposition of the Orders Ophioglossacece and Filices. 



SYNOPSIS OF GENERA. 



Cohort Filicine.^:. 



Vascular Cryptogamia liaving leaves or fronds usiially raised on a stalk, rising commonly from a creeping or 

 assurgent or even erect rootstock, and bearing on the back or margins sporangia containing spores of but one kind, 

 wliich in germination produce a minute cellular prothallus, on which are borne antheridia and archegonia, the 

 latter after fertilization producing a new plantlet. Stems never hollow, nor covered with subulate leaves. 



Okder OPHIOGtOSSACE^E. Leafy plants ; the leaves (fronds) simple or branched, often fern-like, erect 

 in vernation, developed from underground buds formed from one to three years in advance, either within 

 the base of the stalk of the old frond or by the side of it, bearing in special spikes or panicles subcoriaceous, 

 exannulate, bivalvular .sporangia, formed from the main tissue of the fruiting segments of the frond. 

 Prothallus underground, destitute of chlorophyll, monœcious. 



1. OPHIOGLOSSUIM. Frond with a posterior simple or forked or palmated sterile segment, and one or more 

 anterior or lateral simple spikes of fructification ; the connate sporangia in a row along each side of the spike. 

 Buds exterior to the ba.se of the stalk. Veins reticulated. 



2. BOTRYCHIUM. Frond with a posterior pinnatifid or compound sterile fern-like segment and an anterior, 



panicled, fertile segment, tlie separate sporangia in a double row on the branches of the panicle. Bud 

 enclosed in the base of the stalk. Veins free. 



Order FH.IC!ES. Leafy plants ; the leaves or fronds circinate in vernation, rising from a rootstock and 

 liearing reticulated sporangia which are homologous with leaf-hairs, being outgrowths from the epidermis. 

 Prothallus above ground, green, monoecious, in some cases producing new plants from unfertilized archego- 



