-2-2 



MORPHOLOGY 



35. This same anomaly, as to the development of long stalks 

 to the cotyledons and their union into a stem-like body, occurs in 

 various ^ici-ie- of Larkspur (notably in the California!) Delphin- 

 ium nudicaule) : but in these the cotyledons develop into a pair 



of ellicicnt liTcen lea\ 68. 



45 47 



3G. A similar elongation of petioles of the cotyledons, but 

 without any union, occurs in a species of Morning (ilory of the 

 plains beyond the Mississippi (Ipoma-a leptopliylla) : the leaf- 

 like cotyledons coming up on their long stalks separately from 

 the ground (Fig. 45) ; the developed plumule rising some 

 time afterward between them. Compare this with the ordinary 

 species (-J."). Fig. 1,"). 1C. -_'.".). and note that the dill'erence is merely 

 that the caulicle in the common Morning ( < lory elongates and the 

 petioles of the cotyledons remain short. 



37. In all instances thus far a single primary root so regularly 

 develops from the lower end of the axis of the embryo (variously 

 named radicle or cauliele) . and forms such a direct downward 



!'!<;. ).". Germination of I|M>HIM-:I leptopliylla; the caulicle not developing, the 

 plumule and the pi-tiolnl rotylnlons rise from unilercrouiul. Dotted line marks the 

 level of tlie soil. 



Kir,, ic. Embryo of a Pumpkin, the cotyledons separated. 47. Same germinated; 



a cluster of routs from tin- l>:isc of caulicle. 



