386 ON SEEDLINGS 



tions, such as those having an indentation at the sides making 

 them falcate, while others are unequal at the base. A third 

 modification consists in cotyledons which are cordate or 

 auricled at the base. Others are worthy of note, but it may be 

 convenient to class them under the head of exceptional cases. 

 Even in the typical oblong form there are numerous minor 

 variations such as linear-oblong, broadly-oblong, oval-oblong, 

 obovate-oblong, or spathulate-oblong. In all cases they con- 

 form to the shape and size of the seed, and the modifications to 

 some peculiarity of the same, the development of the embryo, 

 the presence or absence of endosperm in the seed, or in a few 

 cases to subsequent growth, i.e. during or after germination. 

 Forms of one, two, or three kinds are peculiar to certain 

 tribes, so that in the subjoined classification it would be con- 

 venient to notice the various kinds occurring in their respective 

 tribes as far as they have come under observation, and to note 

 there the exceptional cases. This applies more particularly 

 to the suborder Papilionaceae than to the Caesalpinieae and 

 Mimoseae, where endosperm is more frequently present, and 

 the embryo is often straight. 



SUBORDER PAPILIONACE^E. 



Tribe Podalyriea. The cotyledons of Chorizema cordi- 

 foliurn (fig. 261) and C. ilicifolium are narrowly oblong and 

 one-nerved. The first two leaves are sometimes opposite 

 and obovate, emarginate, or obcordate, succeeding ones being 

 alternate. Four pairs of the primary leaves of Pultensa 

 daphnoides are opposite, narrowly obovate, generally apicu- 

 late, and aU are simple. Podalyria australis has broadly 

 oblong cotyledons and alternate leaves, the first being obovate 

 and simple, while succeeding ones are digitately trifoliolate. 

 A very striking exception occurs in Viminaria denudata (fig. 

 262), with linear cotyledons. The leaves show a curious case 

 of the gradual abortion of the lamina and the elongation of 

 the petioles. The seventh, eighth, and ninth have three 

 minute teeth at the apex of the petiole as the representatives 

 of as many aborted leaflets. 



Tribe Genifttea. Cotyledons conforming to the leading, 



