374' Mr. R. Brown on the development of the Embryo. 



in the pollen of Pirnis does not necessarily lead to the adoption 

 of Dr. Schleiden^s theory. With respect to Cycadea, whatever 

 opinion may be adopted as to the precise mode of action of the 

 pollen in that family, it is certain that the mere enlargement of 

 the fruit, the consolidation of albumen, and the complete foraia- 

 tion of the corpuscula in its apex are wholly independent of male 

 influence, as I have proved in cases where pollen could not have 

 been applied, namely, in plants both of Cycas and Zamia [Ence- 

 phdartos) producing female flowers in England at a time when 

 male flowers were not known to exist in the country. 



EXPLANATION OF PLATE VIL 



Fig. 1. A scale of the cone of Pimis si/lvesfris, with its winged seeds, one of 

 which is abortive : natural size. 

 N.B. The remaining figures are more or less magnified. 



Fig. 2. An unripe seed, of which the testa, in this state cartilaginous, is cut 

 open, pcirtly removed and thrown back to show the included body, 

 which is the half-ripe original nucleus with its sphacelated apex 

 and the free portion of the inner coat, extending from the apex to 

 about one-third of the length of the nucleus, below which it is in- 

 timately connected with and inseparable from the outer coat. 



Fig. 3. The amnios or albumen, with the coats opened and laid back. 



a. The body of the albumen, with its slightly concave upper extre- 

 mity : in this stage separated from b, the apex, which is conical 

 above, below cylindrical, and which was suspended from the top 

 of the original nucleus. 



Fig. 4. A plan rather than actual representation of a longitudinal section of 



any one seed examined, but the parts accurately copied from the 



calyptrseform membranes, the funiculi or suspensors, and the 



nascent embryos of seeds of Pinus syloestris. 



In this stage the funiculi are distinct from the calyptrseform membranes 



within which they originated. 



Fig. 5. is also a plan of the slightly concave apex of the amnios or albumen, 

 with its semitransparent points or pores circularly arranged ; in 

 this species (Pimtfi sylvestris) seldom exceeding five, and not un- 

 frequently being only four or even three. 



Fig. 6. One of the funiculi or suspensors, with its dilated upper extremity, 

 to which the lacerated remains of a thin transparent membrane ad- 

 here : the funiculus itself ramified, each of the two lateral branches 

 consisting of a single elongated tube or cell terminating in a rudi- 

 mentary embryo : the trunk of the funiculus composed of several 

 (apparently four) tubes or cells terminated by a single embryo, 

 which is already slightly divided, the divisions being the com- 

 mencement of its cotyledons. 



Figs. 7 and 8. Two other funiculi belonging to the same seed less advanced, 

 but both ramified. 



Fig. 0. A funiculus of Pinus pinaster with its thickened head, in which the 

 nuclei of its component elongated cells or tubes, and its adhering 

 lacerated membrane are visible. The figure is given particularly 

 to show that in this (the only one observed) there is no opake gra- 

 nular portion of the compound funiculus ; in other words, no indi- 

 cation of a nascent embryo. 



Fig. 10. A funiculus of Pinus Abies, Linn., with its rudimentary embryo 

 and thickened head, still partly inclosed in the calyptrseform mem- 

 brane. 



