204 THE HISTORY OF CREATION. 



of attraction and repulsion in the particles or molecules — in 

 fact, to the motional phenomena of matter. 



Now, before we turn our attention to the second function, 

 the phenomenon of Adaptation or Mutability, which counter- 

 acts the Transmission by Inheritance, it seems appropriate 

 first to cast one more glance at the various manifestations of 

 Heredity, which we may perhaps even now denominate the 

 " laivs of transmission by inheritance.^* Unfortunately, up 

 to the present time very little has been done for this most 

 important subject, either in zoology or in botany, and almost 

 all we know of the different laws of inheritance is confined 

 to the experiences of gardeners and farmers. It is not 

 therefore to be wondered at, that on the whole these exceed- 

 ingly interesting and important phenomena have not been 

 investigated with desirable scientific accuracy, or reduced 

 to the form of scientific laws. Accordingly, what I shall 

 relate of the different laws of transmission are only some 

 preliminary fragments taken out of the infinitely rich store 

 which lies open to our inquiry. 



We may first divide all the difierent phenomena of inherit- 

 ance into two groups, which we may distinguish as the 

 transmission of inherited characters, and the transmission of 

 acquired characters ; and we may call the former the con- 

 servative transmission, and the latter the progressive trans- 

 mission by inheritance. This distinction depends upon the 

 exceedingly important fact that the individuals of every 

 species of animals and plants can transmit to their de- 

 scendants, not only those qualities which they themselves 

 have inherited from their ancestors, but also the peculiar, 

 individual qualities which they have acquired during their 

 own life. The latter are transmitted by progressive, the 



