929 



lobes, which are of a large size : from the lower surface of the space 

 composed of these cellules a number of small fibrils are sent out, 

 which penetrate a short distance into the soil, and supply the whole 

 cellular body with nourishment. They are most numerous under what 

 may be termed the base of the primary frond, namely, where the 

 lamina first begins to widen ; and between this and the bottom of the 

 sinus is the space on which the little knot of cellular matter is 

 elaborated, in which the first gyrate frond and the radicle originate. 



" The process by which this is produced consists, in the first 

 instance, in the emission, from the lower surface of the above-men- 

 tioned cellules, of a number of others, generally much larger in size, 

 of an hemispherical form, and proceeding at right angles to the plane 

 of the cellules on which they originate. These arise very near to 

 one another, and some unite into a confluent mass, forming a thick 

 coating on the surface of the other cellules. From this coating 

 others are protruded, which in like manner become confluent, arid 

 this cellular mass, tapering as it accumulates, terminates in a blunt 

 or rounded point. 



" Previous to the development of the frond and radicle, a further 

 accumulation takes place at the summit of the cellular knot, which 

 now begins to swell out at two opposite points. The form of the 

 knots varies in different species. In some it is round or hemispheri- 

 cal ; in others nearly flat or even hollow, in which case the cellular 

 swelling is on the upper surface (sometimes, but very rarely, the knot 

 itself is produced on the upper surface) ; some, again, are surrounded 

 by short detached filamentous processes, originating on their surface, 

 and composed of elongated, almost colourless cellules. These are 

 the incipient paleae or scales which surround the caudex of some 

 ferns in a more advanced state; in some species, indeed, they assume 

 the characters of flat, tapering, incurvate, membranous paleae even 

 before the gyrate frond is developed. 



" There is a remarkable similarity in the appearance of the cellular 

 knot at this stage of its growth to the formation of the gemmae or buds 

 produced in the axillae of the leaflets, and on the surface and the mar- 

 gin of the fronds of some ferns, such as Polypodium proliferum, 

 Asplenium viviparum, &c. In the latter case, however, several fronds 

 are developed before any root appears, but in the former the first 

 gyrate frond is almost uniformly preceded by a root. 



" The production of the important body above alluded to, is the 

 ultimate end and effort of the primary frond, and as it is the point at 

 which gyrate development commences, it may be regarded in the light 

 Vol. in. 6 d 



