134 THE OAK 
The seed proper fills up the entire cavity en- 
closed by the fruit-wall above described. It consists 
of a relatively very thin testa, or seed-coat, closely 
enveloping the large, straight embryo (fig. 36, 7). At 
the broad end the funicle can be observed attaching the 
seed to the base of the acorn; it is inserted laterally, 
and traces of the aborted ovules may sometimes be 
found at the point of insertion. The vessels from the 
funiculus bra:ica at the chalaza and ramify in the testa. 
The testa is a shining, pale-brown or yellowish skin, 
consisting only of a few rows of cuboidal, thin-walled 
parenchyma cells, the outer rows of which may be the 
integuments, and the innermost possibly belong to the 
remains of the nucellus; or the latter may be repre- 
sented by the outer portion of the thin membrane which 
includes all that remains of the embryo-sac. A few 
feeble vascular bundles run through the testa (fig. 37, G). 
The testa is closely applied to the surface of the 
two stout cotyledons. These fill up by far the greater 
part of the space enclosed by the thin testa and pericarp, 
and their shape is almost described in saying that. 
Each is a colourless, hard, plano-convex body, face to 
face with the other by the flat surface (fig. 36); a trans- 
verse section of the acorn shows each cotyledon occupy- 
ing half the circle. At the more pointed end of the 
acorn these two cotyledons will be found to be joined 
to the very small embryo (plumule and radicle) by what 
will on germination lengthen into very short stalks 
(petioles), but which are at present mere bridges of 
