«k 



SIR J. LUBBOCK PHTTOBIOLOGICAL OBSEUVATIONS 



373 



the arrangement is very similar, tTie inequality in the two sides 

 of the cotyledon is due to the inequality between tlie two sides 

 of the seed (fig. 80). 



Fig. 86. 



Seed of Laburnum vuJgare, X 0. OC, outer coat ; IC, inner coat. 



In Heritiera macrophjlla the cotyledons fill the seed, which 

 conforms to tlie shape of the carpels, and the fact that these are 

 somewhat unequal -sided renders tlie seed and consequently the 



cotyledons so likewise. 



In the Lnpines the seeds are obliquely oblong, compressed 

 laterally, and without perisperm, the embryo being large, fleshy, 

 yellowish, and occupying tlie whole seed. It is doubled on itselt, 

 and the cotyledons are folded along the radicle, which nearly equals 

 them in Icn-th, with the smaller halves turned towards the radicle, 

 and in such a manner that they and the radicle together occupy 

 one half of the seed, and about equal the larger halves of the 



cotyledons, which fill the other. ' 



In Triphasia the inequality is due, partly at any rate, to a 

 differeiit cause. The seeds are oval, somewhat flattened, especially 

 on the ventral aspect. The embryo is large, and occupies the 

 whole seed. The cotyledons are very unequal in size, and the 

 smaller one is more or less enclosed in the larger. But in addition 

 to this, there are often, indeed generally, two and sometimes 

 three embryos in each seed ; these diff-er in size, and the smaller 

 ones often intrude more or less on one of the cotyledons belong- 



ing to the larger ones. 



Crenate Cotyledons. 



The vast majority of plants have the edges of the cotyledons 

 entire. There are some few, however, in which they are more or 

 less crenate, as for instance in Cordia svhcordata (RgS^). 



In this species the embryo occupies the whole of the ovoid- 

 conical seed. There is no perisperm, and the cotyledons, m order 



LINN. JOUEN. 



XXII 



