276 Mr. Griffith on the Ambrosinia ciliata of Roxburgh. 



Tab. XII. 



Fig. 17. Ovule nearly perfectly developed, outer face. 



Rig. 18. Ditto, longitudinal section. The testa is seen to be cellular where it surrounds the 

 nucleus, almost membranous and diaphanous where it is in apposition with the 

 plumula. The nucleus is seen closely embracing the cotyledon. The section of 

 the exserted portion of the embryo presents a fleshy mass ; the plumulary pro- 

 cesses are already highly developed, and have already assumed a greenish tint, 

 especially the innermost : they are longer than the testa. 



Fig. 19. Capsule shortly after dehiscence and before the valves have become re volute. The 

 dissepiments are attached to the free central placenta. Several ovula are visible 

 lying on the inner faces of the valves. 



Fig. 20. Transverse section of a capsule before dehiscence : — natural size. 



Fig. 21. Fully developed embryo, detached. This must be done with care, as the cotyledon 

 separates very readily: a. the subglobular pisiform cotyledon; b. the radicle; 

 c. the enormous plumula. 



Fig. 22. Seed, the testa of which has become ruptured, and in which the separation of the 

 cotyledon has taken place. The nucleus is seen forming a globular brownish 

 body near the hilum. 



Fig. 23. Longitudinal section of the testa and nucleus of a seed after the separation of the 

 cotyledon has taken place. The cavity of the nucleus is seen to be filled with 

 the separated portion of the fleshy firm cotyledon. 



Fig. 24. Embryo, a short time after the separation of the cotyledon ; the inner processes 

 have begun to be expanded, and an accessory radicle is formed. This represents 

 the first period of germination. 



