764 THE POPULAR SCIENCE MONTHLY. 



and present of man have been enormously developed. Old, worn-out, 

 useless theories have been discarded, new facts have taken their places, 

 discoveries have followed discoveries, each discovery helping to form, 

 link by link, the chain of human history. 



We are beginning to perceive that we are but yet young in the 

 knowledge of human history, that we have as yet picked up but a 

 bright pebble of thought or glittering shell of theory, while before us 

 lies the whole vast sea of human history unexplored. That we are be- 

 ginning to acknowledge this is a good sign, for, when a man or man- 

 kind acknowledge their ignorance, they have at least a sure founda- 

 tion to build uj)on. 



Again, the spirit of bigotry, the spirit that told men to scorn and 

 deride Galileo and Columbus, is fast passing away, and in its stead 

 comes the spirit of rationality, a spirit that tells men to look upon a 

 new idea or theory, even if it does run outside of the accustomed rut, 

 with a reasoning if not favorable eye. And we have faith, as science 

 grows to grander proportions and dispels some of the mist that now 

 envelops it, that some day not far distant will bring forward an his- 

 toric Edison that shall bring together the faint voice of the prehis- 

 toric past and the bright, clear voice of the present ; that some future 

 Champollion will discover, among the ruined cities of the Americas, 

 an American Rosetta-stone that will complete the chain of human his- 

 tory. " The noblest study of mankind is man." 



-- 



MICRO-ORGANISMS AND THEIR EFFECTS IN 



NATURE. 



By WILLIAM S. BARNARD, Ph. D., 



PROFESSOR OF INVERTEBRATE ZOOLOGY IN CORNELL UNIVERSITY. 



WHAT is too small to be seen, people are generally apt to regard 

 with contempt or indifference, as of no practical consequence. 

 This is one of the grossest of popular errors. There is not only a pro- 

 found scientific interest in the realm of microscopic life, which is every 

 day becoming deeper as its organisms are viewed from the standpoint 

 of evolution, but they have a significance in the economy of nature, 

 a usefulness to man, and a value in the industrial arts, of which but 

 few glimpses have as yet been popularly obtained. To the inquiry, 

 Of what service are those swarms of infinitesimal objects which are 

 revealed only through the microscope ? do they subserve any other 

 purpose than to amuse infatuated microscopists ? the reply is, that 

 their operations in nature are on a grand and imposing scale, and 

 that their influence on man and other organisms, as well as on the 

 air, the water, and the solid earth, is nothing less than enormous. 



