134 THE OAK. 



straight embryo (Fig. 36, i). At the broad end the fu- 

 nicle 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 branca 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 inclosed by the thin testa and pericarp, and 

 their shape is almost described in saying that. Each is 

 a colorless, hard, plano-convex body, face to face with 

 the other by the flat surface (Fig. 36) ; a transverse sec- 

 tion of the acorn shows each cotyledon occupying 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 tissue, across 

 which minute vascular bundles run from the embryo 

 into the cotyledons. If the shell-like investments de- 



