BOTA^^CAL SUBJECTS. 



211 



Still more plain is the date-seed in germination, Fig. 67. We 

 have here a bud-scale (6) invaginating the stem, and having the 

 cotyledon (a) at its apex; while (c) is a second bud-scale in- 

 vacrinatino; the terminal bud. 



Then the embrj'o of Ouviraiidra fenestralis. Fig. QS, leaves us 

 in no doubt whatever on this point. The thick part (a) is the 

 cotyledon, while the thin part {b) is the plumule ; that is, the 

 plumule is in the axilla of the glume-like thickened cotyledon. 



Fig. 67. Seed of Date, germinating (Sachs' " Phys. of Plants," Fig. 236). 



In the stipules and bracts of the Begonias we seem to have 

 repetitions oi cotyledons, the leaf proper corresponding to a branch, 

 while they function as bud-scales to that branch while young. 



In Fig. 69 we have a good illustration of the leaf petiole 

 continuing as a stem. It is what Bruant calls the fertile leaf of 

 Begonia AmelicB. (a) is the scar left by the deciduous stipule ; 

 (b) is the leaf-blade, which is at the same time the bract or bud- 



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