

ORGANIC LIFE. 339 



action in the globe itself, that the oldest mythical represen 

 tations of many nations ascribe to these forces the produc- 

 tion of plants and animals, and represent the epoch in which 

 the surface of our planet was unenlivened by animated forms, 

 as that of a primeval chaos of conflicting elements. But 

 investigations into primary causes, or into the mysterious 

 unresolvable problems of origin, do not enter into the domain 

 of experience and observation ; nor has the obscure com- 

 mencement of the history of organisation a place in the de- 

 scription of the actual condition of our planet. ( 42 ) These 

 reservations once made, it should still be noticed in the 

 physical description of the world, that all those substances 

 which compose the organic forms of plants and animals are 

 also found in the inorganic crust of the earth ; and that the 

 same powers which govern inorganic matter are seen to pre- 

 vail in organic beings likewise, combining and decomposing 

 the various substances, regulating the forms and properties 

 of organic tissues, but acting in these cases under conditions 

 yet unexplained, to which the vague term of " vital phse- 

 nomena" has been assigned, and which have been systemati- 

 cally grouped according to analogies more or less happily 

 imagined. Hence has arisen a tendency of the mind to trace 

 the action of physical forces to their extremest limits in the 

 development of vegetable forms, and of those organisms which 

 are endowed with powers of voluntary motion : and here, 

 also, the contemplation of inorganic nature becomes con- 

 nected with the distribution of organic beings over the sur- 

 face of the globe, i. e. the geography of plants and animals, 

 Without attempting to enter on the difficult question of 

 " spontaneous motion," or the difference between vegetable 



