9 6 



CYC AD EAR, MEDULLOSEAE. 



these bundles belong to stalks similar to the others and lying between them 

 but arrested in their development, as I suspect is the case, I have not yet 

 certainly established. The members of the tuft diverge above and increase 

 in thickness. Thus arises an elliptical cone with a nearly even surface 

 formed by the perfect cohesion of the apical portions of all the constituent 

 members (Fig. $A). The seeds, which in the specimens examined appear 

 to be perfectly ripe, are present in large numbers and form a superficial 

 layer in the cone. Each of them occupies a small cavity which communi- 



FIG. 5. Fructification of Bennettitcs Gibsonianus, Carr. A diagrammatic representation of the fructification-cone. 

 Its thick leafy stem enlarges at the apex into a. succulent cushion, from which rise a crowded tuft of numerous stalk- 

 like objects, each traversed by a vascular bundle ; the stalks unite with one another at the periphery and form a con- 

 tinuous surface. Each stalk bears at its apex a seed which lies in a pocket-like depression. B representation of the 

 longitudinal section of a seed, to some extent diagrammatic and constructed from several distinct figures ; a the entering 

 vascular bundle : b its expansion at the base of the nucellus ; c the embryo with the two cotyledons ; d the testa 

 formed of stout lignified palisade-like cells, which is prolonged above into a tubular process d' terminating obtusely 

 on the surface of the cone, and probably answers to the integument ; e tubular cell-layer, the continuation of a delicate 

 membrane surrounding the embryo, and possibly answering to the outer boundary of the nucellus ; the tubular process 

 at its apex represents the apex of the nucellus surrounding the pollen-chamber. C portion of the transverse section 

 through the tuft of seminiferous stalks beneath the place where the seeds begin (a a in the diagrammatic 

 representation of the entire cone) ; at a the transverse sections of the enveloping lanceolate leaves which spring 

 from the stalk ; at d the stalks with their central bundle surrounded by a gap in the tissue; between them small 

 transverse sections squeezed out of shape which belong either to intermediate leaves or to arrested seed-stalks ; in the 

 periphery at c there are only such small transverse sections, which are here flattened ; b represents the superficial 

 homogeneous layer of the cone, which is formed by the perfect coalescence of the extremities of the entire tuft of 

 organs. The whole from preparations lying before me and made from material preserved in the Museum at Kew. 



cates with the outside by means of a narrow canal and orifice 1 . In its 

 base is the termination of the vascular bundle of one of the stalks which 

 have cohered in the surface of the cone. , Each of them therefore bears an 

 ovule at its summit. If a section of a seed is made in the direction of its 

 axis (Fig. 5 B), it is seen to have arisen from an atropous ovule ; the 

 vascular bundle spreads at the base of the nucellus into a small disk-like 



1 Carruthers (4), t. 59, f. 6. 



