76 



STRUCTURAL BOTANY. 



[63, 64. 



above; or of the Oak, as displayed in figures 1, 2, 3, 

 4 ; or the Pea, or Squash, and other Dicotyledons ; and 

 the chief difference observed among them will be in 

 the disposal of the cotyledons. In general, these arise 

 with the ascending axis, as in Maple and Bean, and 

 act as the first pair of leaves. But sometimes, when 

 they are very thick, as in Pea, Buckeye, and Oak, they 

 never escape the seed-coats, but remain and perish at 

 the collum ( 199), neither ascending nor descending. 



35 



Germination of the Maple. "22,5, Samara ; section showing the folded cotyledons at c. 226-230, Pro- 

 gressive stages. 



193. The germination of MONOCOTYLEDONS, as seen 

 in Indian Corn, Wheat, and Tulip, is in this wise. The 

 cotyledon is not disengaged from the seed, but remains 

 stationary with it. The radicle (r) protrudes slightly, 

 and one or more rootlets (s) break out from it and 

 descend. The plumule (c) shoots at first parallel with 

 the cotyledon along the face of the seed, but soon 

 ascends, pushing out leaf from within leaf. 



194. The conditions requisite for germination are 



