FERTILISATION AND PROPAGATION. 



117 



mentioned that the oospore, at a very early period, divides into eight cells, 

 in two layers. Of these cells, four lie next the base, and four next the front, 

 of the prothallus. Of the latter, the two farthest from the neck of the 

 archegonium give origin to the first leaf or frond ; one, near the neck, to 

 the growing point of the stem ; and the fourth to hairs. Of the other four 

 cells, one, opposite to the stem, develops into the root, one ultimately 

 disappears, and the other two form the " foot " of a structure that remains 

 sunk in the archegonium, which has grown so as still to surround the foot 

 (see Figs. 8 and 9). By means of this organ the young plant absorbs 

 nourishment from the prothallus, which, for a time increases in size, but is 



Fig. 8, Diagrammatic Sketch of Connection of 

 Young Fern with Prothallus, 



f, Foot of young Fern imbedded in Hollow of enlarged 

 Archegonium (<x) ; fr, Very young Frond of Fern ; 

 p, Prothallus ; r, Root of Fern ; rh, Root-hairs of 

 Prothallus. 



Fig. 9. Young Fern growing from Prothallus 



(slightly enlarged). 



fr, Young Frond of Fern ; p, Lower Surface of Prothallus ; 

 r, Root of Fern ; rh, Root-hairs of Prothallus. 



gradually exhausted and withers away, and afterwards the young Fern is able 

 to nourish itself by its own roots, and leaves. 



Such are the complicated but exceedingly interesting phenomena resulting 

 in the fertilisation of the spore and in the reproduction of Ferns in general, 

 and for the clear exposition of which we are much indebted to Mr. George 

 Nicholson's " Dictionary of Gardening."* 



Propagation. 



There are several ways by which Ferns can be, and are usually, repro- 

 duced : by spores, by the division of the crowns, by the sectioning of the 

 rhizomes, by the rooting of the proliferous growths found on the surface of 



* " The Illustrated Dictionary of Gardening." Edited by George Nicholson, A.L.S. London : 

 L. Upcott Gill, 170, Strand, W.C. 



