182 BOARD OF AGRICULTURE. 



tion, are governed by precisely the same laws, bearing in 

 mind throughout the effect of complexity produced by envi- 

 ronment, and the influences predicated on the general laws 

 involved. We have thus hoped to have established the con- 

 nection of the law of persistence of force with vital operations, 

 and its importance as offering an explanation for all the facts 

 involved in the consideration of evolution. 



Biological science is under the control of those great laws 

 which regulate the cosmos, and the law of the persistence of 

 force is the chain which, permeating life in all its branches, 

 links its phenomena with those of the universe. Evolution is 

 not the cause of changes of animal forms and instincts ; it is 

 not merely an expression of the observed facts of animal 

 advancement ; it is an expression of the process of develop- 

 ment under the law of persistence of force. When this beau- 

 tiful law is once apprehended, there can be no escape from 

 the deductions which are seen to flow directly from it. 



In studying the phenomena attending the breeding of 

 domestic animals, we have in this law the key for the investi- 

 gation of the observed changes, and the science of breeding 

 is established. With study and observation all practical 

 details which are precisely apprehended can be seen to be so 

 connected with previous and existing phenomena, through the 

 expression of this law of persistence, as to constitute a science ; 

 for science is nothing more than the tracing the lines accu- 

 rately between effects and their preceding causes. 



APPLICATIONS. 



There are many operations of nature, otherwise inscrutable 

 in their relations, which appear to be explained through this 

 law of persistence of force. Under the consideration of effects 

 through law, phenomena become linked with phenomena, 

 observations become more exact, and the horizon of our inves- 

 tigation becomes cleared. Let us see how far the theory we 

 have herein developed will serve us in the consideration of 

 those changes, which may be grouped in detail under the title 

 of subordinate laws of inheritance. 



We will just call attention to what we have claimed in our 

 context, that heredity is itself developed in strict conformity 

 to the principles developed by this law. For the new force, 



