Mr. GnirriTB on the Ambrosinia ciliata of Roxburgh. 271 
the plumula ; it is cellular towards its base and where it surrounds the dense 
internal globular body, membranous throughout the rest of its extent, = 
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 between 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, ofa 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 laminz 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 
