Mr. Griffith on the Ambrosinia ciliata of Roxburgh. 271 



the pluimila ; it is cellular towards its base and where it surrounds the dense 

 internal globular body, membranous throughout the rest of its extent, and 

 so thin that the processes of the plumula are visible through it, and give to it 

 a greenish tint. The nucleus is dense, indurated, nearly globular, the original 

 neck having nearly disappeared. It is of a brownish tint, and contains and 

 firmly embraces the inclosed descending portion of the embryo, which is the 

 cotyledon. There is however partially interposed becween them the lining 

 cellular membrane, which occupies only the fundus of the cavity. 



The embryo is of a singular shape. Its descending portion or cotyledon is 

 clavate and nearly entirely inclosed within the nucleus ; the inclosed part 

 separating with that body exceedingly readily, and subsequently, about the 

 time of dehiscence of the fruit, spontaneously. The tissue of the inclosed part 

 is firm and more dense than the short uninclosed part. The exserted portion 

 of the embryo consists, exclusively of the base of the cotyledon, of a fleshy, firm, 

 plano-convex body. The plane part is depressed towards the centre, to which 

 the base of the cotyledon is attached. From one side of this the radicle pro- 

 jects, which is still conical and acute, and is always directed from the pla- 

 centa, and generally outwards, but often laterally, and always more or less 

 downwards. The circumference of the convex part is entirely occupied by 

 the processes, constituting an enormously-developed plumula. These are 

 densely imbricated, intermixed with abortive and rudimentary ones, and of 

 immense length, especially the outermost, which are about one inch long. 

 They are all subulate with the exception of the two or three innermost ones, 

 which resemble rudimentary leaves, and are divided into a limb, which is 

 convolute, and a petiole, which is likewise convolute, the innermost inclosing 

 in its fold an extremely minute rudimentary leaf. The outermost are the nar- 

 rowest, the bases as we proceed inwards becoming gradually dilated. They are 

 all deflexed and tortuous, especially the outer ones. Their extreme apices are 

 invariably brown, and as it were sphacelated. The colour is green, increasing 

 in depth as we proceed inwards, the convolute laminae of the innermost being 

 of a rather deep tint. These processes are furnished with vessels, but their 

 chief bulk is cellular, the cells containing a considerable number of green 

 globules. They are, with the exception perhaps of the outermost, furnished 

 with stomata. These bodies however appear to be perfect in the interior 



