366 



SIR J. LUBBOCK PITTTOBTOLOGTCVL OBSEUVATIO^S. 



edge to the placenta, surrounded by a paler margin, glabrous 

 and white ; the hilum is small, and on the middle of the yeutral 

 edge. The embryo is, in the mature seed, much curved, em- 

 bedded iu, but lying near the outer edge of, the perisperm. The 

 radicle occupies the lower and narrow part of the seed. The 

 cotyledons are linear, not broader than the radicle, curved, with 

 their tips close to the hilum, and their back to the placental axis, 

 and at right angles to the plane of the seed, the whole width of 

 which accordingly they occupy, so that they cannot grow any 

 wider. On the other hand, while the fruit of Oestrum is not very 

 unlike that o^ Solanum^tha seeds are very different in shape, being 

 peltate, more or less obovate, with the broad end towards the 

 apex of the seed, so that the cotyledons have room to widen 

 themselves. 



Sometimes we meet with species having both narrow and broad 

 cotyledons, even in the same genus. For instance, Coreopsis fili- 

 folia (fig. 6) has narrow, Coreopsis aitriculata broad, cotyledons. 



Fig. GO. 



Fig. r>i. 



Fig. 62, 



Fig. 63. 



Coi^eopsis JiUfolia, 



Fig. 60. Achene, X 14. Fig. Gl. Longitiulinal section, X 14, 

 Fig. 62. Transverse section, X 14. Fig. 63. Embryo, X H. 



P 



fi 



(fig. 64) 



