84 BIOLOGICAL LECTURES. 



is troubled with trusts, monopolies, strikes, theories of taxa- 

 tion, of protection, of values, of liberty, of free-will, of the 

 family, of education, of heredity, of life itself ; and who shall 

 deliver us ? To say that science will may be true enough, but 

 she cannot to-day. 



In his Locksley Hall Tennyson wrote more than fifty years 



ago 



" Science moves but slowly, slowly, 

 Creeping on from point to point." 



And that was true then, and in large measure is true to-day, 



concerning all those matters that relate more nearly to us in 



our everyday lives. When we laud science, and tell how 



much has been accomplished within the past fifty years, it is 



just as well to remember that what has been achieved in this 



domain has been mostly in the purely mechanical field. We 



feel quite sure we now know how the Solar system came to be 



as it is, — through a series of slow changes by which a huge 



molecular cloud of dust in space becomes a body of rotating 



globes revolving about a central hot mass. We feel quite 



confident that what we call the doctrine of energy is true, and 



that it is not created or annihilated by any processes in our 



experience. We are almost, if not quite convinced that the 



animals and plants upon the earth to-day are the descendants 



in unbroken line from the simplest microscopic forms of living 



things in the far off geologic ages, and we put all these things 



together and call the process of becoming something different, 



— evolution; and for convenience we call some mechanical 



science, and some molecular science, and some biologic science, 



according as the subject-matter is among big bodies or little 



bodies or living bodies. But it is sometimes forgotten or 



overlooked that the same forces are at work with the little as 



with the big bodies, and that no body, large or small, can be 



separated from the action of all the rest, and that no particle 



of matter ever lets go its grip on any other one. These things, 



I have said, we think we know ; but may I not say we do knoiu, 



if we really do know anything.? If there be any doubt about 



gravitation, about the laws of energy, about the multiplication 



table, then one may harbor doubts about any thing he pleases ; 



