170 ZOOCHEMICAL PROCESSES. 



simultaneously scattered over its surface; we know that for 

 thousands of years an exuberant vegetation covered our globe, 

 before the sun had matured the first germ of animal life ; and we 

 are equally convinced that it was only subsequently to the most 

 recent revolutions on the earth's surface that the higher animals 

 were created, and that, last of all, Man appeared. But here the 

 physical sciences lead us to a boundary, which we distinctly re- 

 cognise as such, and know that we can never pass, without leaving 

 the domain of physical inquiry for the regions of metaphysics. 

 But it does not follow that because we are unable to recognise the 

 origin of certain natural phenomena, we may not be capable of 

 comprehending their subsequent course. The human mind does 

 not turn aside from the study of the movements of the heavenly 

 bodies, because it does not, and never can hope to know the 

 origin of their motion ; and its efforts have been successful in 

 attaining the most exact acquaintance with the laws of those 

 motions, and the course of the motion when once imparted, and 

 has even been able to predict what those motions will be at a 

 future period; for the laws remain everlastingly unchanged, 

 although the primum movens cannot be recognised after it has 

 once imparted the motion which obeys the laws. Thus, too, in 

 respect to the primary formation of organised bodies, either as 

 seeds or ova, no investigation will ever show how the germ 

 originated, or what regulated the first creation of ova and seeds ; 

 yet, notwithstanding this, we are as well able to investigate the 

 laws of the organic motion that has been induced, as to study the 

 regular movements of the heavenly bodies in their orbits ; for, as 

 in the regions of space, the first moving force merely gave the 

 impulse to motion and regularity, and did not again, by renewed 

 influence, affect the motion imparted to the created body, so also 

 when the force by which the germ was generated, had implanted 

 in it the laws necessary to effect its development, and to control 

 its further elaboration and assimilation, it ceased to interfere with 

 the laws it had established; it gave to the living organism no 

 guide or guardian by whose agency the sacred laws of its being 

 were to be modified or miraculously suspended. The true miracle 

 of nature is the unchangeable regularity of the course of all 

 phenomena. Since, therefore, conformity to law has been im- 

 planted in organised bodies, we may hope, although perhaps at a 

 later period, to examine the laws of organic nature as accurately 

 as previous generations succeeded in elucidating the physical laws 

 of cosmical phenomena. 



Although in our study of the animal organism we frequently 



