tJie Ovula «/"Loiantlius «»^/ Visciiin. 73 



Tlie fully developed embryo is oblong-, clavate, the radicle forming the 

 thickest part; there is a slight narrowing about the j miction of the cotyle- 

 dons with the radicle. In the centre of this part two oblong foveolœ or sulci 

 are observable, which owe their existence to the non-union of the bases of the 

 cotyledons*. The plumula is small, but totally concealed, unless indeed the 

 cotyledons are cut away. The embryo is attached very slightly by a very fine 

 short membrane, the originally long funiculus having disappeared. This dis- 

 appearance is, I imagine, not real ; probably the tissue of the funiculus contri- 

 butes to the formation of the embryo. The coloration of the embryo keeps 

 pace with its development. Throughout its first stages it is colourless ; the 

 green colour is first visible about the time that the division of the cotyledons 

 appears, and it continues increasing as the embryo approaches nearer and 

 nearer to a state of perfection. 



At this time it is entirely green, tlie colour differing however in tint ; the 

 radicle, particularly towards its apex, being tinged with yellow. The greatest 

 development of green is at the base of the cotyledon, about the sulci or clefts. 



With respect to the changes that have taken place at the time of maturity 

 of the fruit in the calyx and ovarium, I must mention the total disappearance 

 of green viscous tissue. The whole cellular substance between the outer 

 layer, or cuticle of the calyx and the ovarium, is converted into a yellowish 

 transparent viscous matter. This is not, however, prolonged down the stalk 

 of the ovarium, which is now fibrous f. With respect to the ovarium, the only 

 remarkable circumstance is the softening down and conversion of a portion of 

 its texture, particularly towards its apex, into viscous tissue. Tliis often occurs 

 to such a degree that the naked radicle is imbedded in the viscous tissue, and 

 is no doubt intended to remove any impediment to the occurrence of germi- 

 nation. 



In two or three other species that I have examined the same phenomena 

 occur ; but in these there was no development of green viscous matter, nor 

 any colouring of the albumen. In one species the cotyledons were consoli- 

 dated, and two natural clefts existetl ; in the other, they were merely applied 

 face to face, consequently no clefts were present or necessary. But inde- 

 pendent of these, and of changes of form dependent on specific difference, 1 



* See Tab. IV. fig. 9. t See Tab. V. fig. 1. 



VOL. XVIII. L 



