TEST OF THEORIES. 71 



new light. It will not be hard to change opinion in such 

 goodly company. 



Professor Agassiz was then introduced, and spoke as follows : 



ADDRESS OF PROFESSOR AGASSIZ. 



The address you have just heard has turned my thoughts so 

 completely in that direction, that, if I were to follow my first 

 intention, I should speak without thinking very earnestly of 

 what I was saying. I ask your indulgence, therefore, if I take 

 up the subject where Professor Chadbourne has left it, and add 

 to what ho has said a few considerations derived from the 

 animal kingdom, which have a similar significance, and have 

 also their application in reference to agriculture. 



This practical business of cultivating the ground and raising 

 plants for special purposes is an awful fact to theorists. This 

 practical business of life, as was well said this morning, in the 

 opening address to the Board, is the test of all doctrines and of 

 all theories ; and those theories, however well supported, which 

 cannot stand that test, have all to go by the board. I look 

 forward to the experience of the farmer to give to science the 

 means of advancing in the direction which is at this moment 

 hampered by mere theories. "We cannot deal either with 

 animals or plants practically without knowing their nature ; we 

 cannot cultivate a crop without knowing the character of the 

 plants which produce the crop ; we cannot raise stock without 

 knowing the nature, the habits and disposition of the species of 

 animals which has been so brought into a state of domesticity ; 

 and it is, therefore, a practical question, which at once touches 

 theoretical views, in the present state of our science, to* know 

 what are the relations of these things which we grow, or which 

 we domesticate to one another, and all those things which are 

 not yet brought under domestication or culture, but which, in 

 their relations to the others, show such an affinity that an 

 attempt at cultivation or domestication may be possible. 



In order fully to understand this subject, we have to deal at 

 once with an abstract question — that of species ; to consider 

 whether there is such a thing in nature as species or not ; to 

 consider what are the things which we call varieties in our 

 gardens, on our farms, or in our stables ; and how these vari- 



