214 Mr. Griffith on the Ovulum q/"Santalum, S^c. 



submammillate base, from which the sac always- seems to arise, e. Embryonary 

 sac. 



Fig. 6. Embryonary sac before fecundation from ovary before expansion of perianthium, 

 surrounded at its attenuate base by nucellar cellular tissue, from one of the cells 

 of which it may be supposed to have originated. 



Fig. 7- Embryonary sac, some time after the fall of the perianthium, with considerable de- 

 velopment in the cellularity of the sac, each of the cells of which are very large, 

 and each for the most part occupied by single grumous masses. At a, the perfo- 

 ration of the sac by the filament b, and the continuity of this with the vesicle c, 

 are shown. Two rather large grumous masses occupy partly the apex of the sac. 



Fig. 8. Embryonary sac, a good deal more advanced. The upper part (except the apex 

 itself) is now subdivided into a good many cells, almost all of which present a 

 nucleus, all being crowded with grume and containing some granules, particularly 

 those in which the nuclei are not evident. The formation of the cells is extend- 

 ing downwards, the base of the sac alone presenting its original membranous 

 hyaline appearance. At a, the perforation of the sac is seen ; the continuity of 

 the vesicle b (which has undergone no change) with the filament d may also be 

 observed. The peculiar manner by which the uppermost series of cells of the 

 sac have commenced, extending, as it were, over the lower edge of the vesicle, is 

 also observable. 



Fig. 9. Apex of an embryonary sac, more advanced, after the action of nitric acid. The 

 vesicle, which is plainly continuous with the protruding filament, now contains 

 many nuclei. 



Fig. 10. Seed from a young fruit 1^^ line long. The apex of the original embryonary sac is 

 now nearly concealed by the encroachment of the cells or young albumen. The 

 opake spot a represents the embryo, which would hence appear to occupy the 

 situation of the original vesicle. 



Fig. 11. Longitudinal section of a more advanced fruit. The viscous tissue does not yet 

 extend around the central tissue and its horns or filaments. The embryo is now 

 oblique. 



