ACTION OF FLOWERS. 67 



turely by grafting it upon an old stock, the effect of 

 which will apparently not be to diminish its vigour, 

 it may be conceived that, in the first place, the seed- 

 ling will receive a considerable quantity of nutritious 

 matter from the old stock, where it has been already 

 collected, and that thus the supply will be greater 

 than the consumption, however large the latter may 

 be ; and, secondly, that, at the time of union of itself 

 with the stock, there will be sufficient interruption of 

 continuity in the bark to oppose some obstacle to the 

 descent from the seedling of whatever matter it may 

 have received or formed. Hence, it is an axiom in 

 vegetable physiology, that the production of flower- 

 buds depends upon the presence of nutritious matter 

 in sufficient abundance for their support. 



86. The use of the calyx and corolla is too uncer- 

 tain and unimportant to demand much notice. The 

 calyx is usually regarded as a protecting organ, and 

 the corolla as a part for the embellishment of the 

 sexes. They neither appear to be of much physiolo- 

 gical importance ; more especially the corolla, or it 

 would not be absent in such large numbers of plants. 



87. The use of the stamens is to effect the fertilisa- 

 tion of the young seed contained in the pistil. To 

 this end, the pollen of the anther must be applied to 

 the stigma ; the result of which is, that an embryo, 

 the rudiment of a future plant, is generated in the 

 inside of the young seed, and, when mature, is capa- 

 ble of multiplying the species. It is, however, to be 

 observed that the seed, when ripe, will not renew the 

 species from which it is derived, with all its indi- 



