18 



SEEDLINGS. 



[SECTION 3. 



upon the surface of the soil, the flat but thick cotyledons remaining in it, 

 and supplying food for tin- irmwlh of the root below and the plumule 

 above. In its near relative, the Tea (Fig. o-i, oa), this use of cotyledons 



29 



for storage only is most completely carried out. For they are thickened 

 to the utmost, even into hemispheres; the caulicle does not lengthen at all ; 

 merely sends out roots from the lower end, and develops its strong plu- 

 mule from the upper, the seed remaining unmoved underground. That is, 

 in technical language, the germination is hypog&ous. 



27- There is sufficient nourishment in the cotyledons of a pea to make 

 a very considerable growth before any actual foliage is required. So it 

 is the stem-portion of the plumule which is at first conspicuous and strong- 

 growing. Here, as seen in 1'ig. 35, its lower nodes bear each a useless 

 leaf-scale instead of an edieient leaf, and only the later ones bear leaves 

 Hied fur foliage. 



Frc. ->'>. Embryo of Pumpkin-seed, partly opened. '27. Fonng seedling of same. 



Fie. ilu-yo of ('mnmnii IVan (I'hascolus vnl.^aris) : caulicle bent down 



y\vr c.l:,v nl' .'Mtyli'ilons. 2'J. Same grnnin.-itiiii: : caulicle well Irirjtlifiinl and root 

 :min; thick cotyledons partly spreading; and plumule (pair of leaves) growing 

 .tctwcon them. 30. Same, older, with plumule developed into internode and 

 ,iair of 



