American Scientific Association. 293 



organisms de nevo ? Do not the views presented above support the 

 doctrines of equivocal generation and the original creation of 

 species by physical force? I answer that the question of the 

 origination of species is left exactly where it was found and where 

 it must always remain, viz., utterly beyond the limits of human 

 science. But although we can never hope by the light of science 

 to know how organism originated, still all that we do know of the 

 laws of the organic and inorganic world seems to negative the 

 idea that physical or chemical forces acting upon inorganic matter 

 can produce them. It is true that vital force is transformed to 

 physical force, but the necessary medium of this transformation is an 

 organized fabric ; the necessary condition of the existence of vital 

 force is therefore the previous existence of an organism. As the 

 existence of physical forces cannot even be conceived without the 

 previous existence of matter as its necessary substratum, so the 

 existence of vital force, is inconceivable without the previous 

 existence of an organized structure as its necessary substratum. 

 In the words of Dr. Carpenter : l It is the speciality of the ma- 

 terial substratum thus furnishing the medium or instrument of 

 the metamorphosis, which establishes and must ever maintain a 

 well marked boundary line between physical and vital forces. 

 Starting with the abstract notion of force as emanating at once 

 from the divine will, we might say that this force operating 

 through inorganic matter, manifests itself as electricity, magnetism, 

 light heat, chemical affinity and mechanical motion ; but that when 

 directed through organized structures, it effects the operations of 

 growth, development and chemico- vital transformations." 



FORMATION OF OCEANS AND CONTINENTS. 



Prof. Le Conte then gave his views in respect to the for- 

 mation of continents and oceans. It was an attempt to prove 

 the truth of the theory of Prof. Airy as to the laws governing 

 bodies floating upon fluids, and considered as explaining the 

 phenomena of continents, oceans, and volcanoes, upon the sup- 

 position that the inside of the earth is fluid and enclosed by a 

 crust. Prof. Le Conte gave an elaborate explanation illus- 

 trated by diagrams of different bodies floating upon water, prov- 

 ing that the under surface of such bodies may be judged of as to 

 their configuration by a simple inspection of their upper surface. 

 " If there is a general rising or depression of the upper surface 

 from the margin towards the middle, we may be absolutely sure 



