478 HISTORY OF PHYSIOLOGY. 



separated us was marked most luminously by this 

 expression." And in the same work he relates his 

 botanical studies and his habit of observation, from 

 which it is easily seen that no common amount of 

 knowledge and notice of details, were involved in 

 the course of thought; which led him to the prin- 

 ciple of the Metamorphosis of Plants. 



Before I state the history of this principle, I 

 may be allowed to endeavour to communicate to 

 the reader, to whom this subject is new, some 

 conception of the principle itself. This will not be 

 difficult, if he will imagine to himself a flower, for 

 instance, a common wild-rose, or the blossom of an 

 apple-tree, as consisting of a series of parts disposed 

 in whorls, placed one over another on an axis. The 

 lowest whorl is the calyx with its five sepals; 

 above this is the corolla with its five petals; above 

 this are a multitude of stamens, which may be con- 

 sidered as separate whorls of five each, often re- 

 peated; above these is a whorl composed of the 

 ovaries, or what become the seed-vessels in the 

 fruit, which are five united together in the apple, 

 but indefinite in number and separate in the rose. 

 Now the morphological view is this ; that the 

 members of each of these whorls are in their na- 

 ture identical, and the same as if they were whorls 

 of ordinary leaves, brought together by the shorten- 

 ing their common axis, and modified in form by 

 the successive elaboration of their nutriment. Fur- 

 ther, according to this view, a whorl of leaves itself 



