EMPIRICAL LAWS. 53 



expected. The growth of an animal from infancy to 

 maturity, of a plant from infancy till death, and even 

 that process of decay which is but a slow death, bear 

 a most striking resemblance to the progressive effect 

 of the continued action of some cause, proceeding 

 until it meets agencies which overpower it, or until 

 its accumulated effects give rise to conditions incon- 

 sistent with its own existence. This supposition by 

 no means requires that the effect should not, during 

 its progress, undergo many modifications besides 

 those of quantity, or that it should not sometimes 

 appear to undergo a very marked change of character. 

 This may be, either because the unknown cause con- 

 sists of several component elements or agents, whose 

 effects, accumulating according to different laws, are 

 compounded in different proportions at different 

 periods in the existence of the organized being ; 

 or because, at certain points in its progress, fresh 

 causes or agencies come in, or are evolved, which 

 intermix their laws with those of the prime agent. 



This great problem, the most difficult in all 

 physics, the ascertainment of the ultimate laws of 

 organized nature, is one which natural science in its 

 progress seems now at least to have fairly come up to ; 

 and a beginning has been made at the point where the 

 phenomena appear most accessible to experiment, 

 namely, in separating the effects of partial from those 

 of general causes. The result, as far as it goes, fully 

 accords with the above surmise. I allude to the new 

 and infant science of morphology, created with 

 respect to animals by the genius of Cuvier and St. 

 Hilaire, and with respect to vegetables by that of the 

 illustrious Goethe, to whom the world owes so much in 

 quite a different field of intellect, and whose researches 

 on the " Metamorphoses of Plants " have met with a 



