CHAPTER IV. 



ACORNS 

 Germination and the Seedlings 



Position and Arrangement of the Embryo 



IN all seeds which have arrived at maturity the embryo 

 radicle, plumule and cotyledons have been perfectly 

 formed within the seed substance before the seed left the 

 mother plant and were we speaking of animal bodies we could 

 say that the foetus had arrived at completion and awaited 

 the moment when it could begin to live its own life. 



The size and arrangement of the embryo differ with the 

 order to which the seeds belong. As Lord Avebury tells 

 us, there are " many whole orders in which the ripe seed 

 is entirely occupied by the embryo ; in other cases, again, 

 as in Delphinium, the embryo is very small, and examples 

 of every intermediate stage might be given. 



" Where it is an advantage to the plant that germination 

 should be rapid, this of course can be more readily secured 

 if the embryo is large. In fact, we find that species with 

 large embryos, such, for instance, as the cabbage or pea, 

 germinate much more rapidly than those, such as Umbellifers, 

 Banunculacece, etc., in which the embryos are small. 



" In albuminous seeds the arrangement of the embryo 

 presents no special difficulties, as the endosperm simply fills 

 up all vacant spaces. In ex-albuminous, on the contrary. 

 Nature has to exercise much ingenuity, and adopt various 

 devices to fill up the whole space." 



The chief difficulty in almost every case seems to be with 

 the cotyledons, which instead of being just ordinary first- 

 leaves, assume all sorts of curious forms. From the last 

 quoted source I learn that " When the testa does not readily 

 split, and where in large seeds there is no endosperm, the 

 difficulty of unfolding the cotyledons and extracting them 



