ON VEGETABLE PHYSIOLOGY. 77 



which it contains, is one of nature's greatest 

 resources in the vegetable world, it is defended 

 above all otber parts of the plants against the 

 accidents to which it may be liable. Thus 

 in the one instance, it is imbedded in the soft 

 pulpy substance of the esculent fruits; in another, 

 it is protected by thick membranes, and inclosed 

 in a pod, as in leguminous vegetables; while in 

 a third, it is surrounded by a hard shell or a thick 

 cuticle (as in the various species of corn), which 

 requires a very strong force to rend it asunder. 

 It is thus fitted for the purpose of future germi- 

 nation the next subject for discussion. But we 

 must previously claim your indulgent attention 

 to a few observations, which a retrospect of the 

 preceding subject has naturally suggested. 



In no part of the vegetable kingdom has nature 

 displayed more ingenuity or greater protecting 

 care than in the instruments of re-production, so 

 necessary to the perpetuation of the species. 

 Thus the ovary, which, from containing the rudi- 

 ments of a future plant, is her principal object, 

 is placed completely at the base of the centre of 

 the flower, supported perpendicularly by the 

 upper portion of the pistil, as the point of greatest 

 security; and being surrounded by a double 

 wall of defence first, by the circular arrange- 

 ment of the stamens, and secondly, by the petals 

 of the corolla, it is completely shut out from all 

 injury, without excluding the light and air so 

 necessary to its existence. 



