FRUIT OF MELOCANNA BAMBUSOIDES. 411 
to be of extreme delicacy. The peripheral endosperm-cells are filled with plasma; the 
inner contain a decreasing amount of plasmatie wall-lining, and, beside their nuclei, a 
great deal of oil and a varying but moderate amount of transitory starch. A portion 
of the oil passes into the liquid filling the embryo-sac, leaving a greasy residuum if the 
liquid is evaporated. Small quantities of starch and free nuclei were also found in the 
liquid, probably escapes from cells which had been cut open. This was the condition of 
the embryo-sac of the young fruit which contained the smallest embryo I observed in 
the course of my investigations. The fruit measured about 2°5 em. across where widest, 
whilst the embryo-sae was up to 1:2 em. wide and 2 em. long. The length of the embryo 
was 3 mm., as already stated, and its distance from the base of the fruit slightly over 
3mm. Imay add that the pericarp at this stage contained scarcely any starch. The 
embryo occupied the base of the ovarial cavity, lying across it. The apex of the ovule 
was no longer discernible, having been crushed and probably in part absorbed by the 
growing embryo. The shape of the embryo (Pl. 45. figs. 22 & 23) at this stage was that 
of an ordinary grass embryo with a flat shield-like scutellum, Plumule and radicle 
had been formed and were in the peculiar position which I shall describe later on. Even 
the bud in the axil of the coleoptile and the initials of the first secondary roots were 
developed, whilst a considerable number of the protocambial strands could be traced 
from the base of the plumule into the scutellum. As the fruit continues to grow the 
embryo-sac and embryo enlarge. The embryo passes basewards and crushes the 
parenchyma below it, until it lies finally close to the surface covered by a coriaceous 
piece of dead tissue (Pl. 45. fig. 3, e£.). This downward movement is facilitated by the 
spongy condition of the parenchyma at the very base of the young fruit. In the case 
figured on Pl. 45. fig. 22, a portion of it (fig. 22, at *) about midway between the embryo 
and the point of insertion of the stalk was even in a state of collapse. Analogous 
conditions occur also in other viviparous plants and have led to the adoption of the term 
* Verdringungsgewebe " (see Goebel, in ‘ Flora, Ixxxiii. 1897, p. 430). Simultaneously 
the plumule develops more leaf-primordia, a few more secondary rootlets are formed, and 
the system of vascular strands gradually assumes the peculiar complicated structure 
characteristic of the mature embryo of Melocanna; but the most remarkable develop- 
ment is that which the scutellum undergoes. Growing from the back which is turned 
towards the cavity of the embryo-sac, it fills the cavity tightly from the base upwards, 
either entirely or with the exception of a small portion at the top. At the BE €— 
the liquid contents of the embryo-sae are absorbed and the endospermatic lining which 
has long before collapsed becomes wedged in between scutellum and pericarp and crushed 
into an apparently structureless (Pl. 46. fig. 29, d.) film. This growth of the scutellum 
is accompanied by the development of very numerous vascular ae (PL 47. 
fies. 40, 51) spreading in sheaf fashion from the base of the scutellum. Towards the 
close of the development reserve stareh is deposited in the parenehymatie ground-tissue, 
whilst the epithelium (Pl. 46. fig. 29, epth.) remains from an early stage filled with 
Before the fruit attains its final size, the pericarp 
ion of the innermost 3 or 4 cell- 
9N2 
| plasma, proteids, and oil in tiny drops. 
also begins to be charged with starch, with the except 
