130 AN INTRODUCTION TO SCIENCE 



as present known is very small which produce effects 

 similar to those produced by microscopic plants. Micro- 

 phytology is not, therefore, an unexceptionable name, but it 

 is better than the term bacteriology, which is commonly 

 used ; since bacteria, properly so called, are not by any 

 means the only organisms with which the science deals. 

 Some common term is needed which would imply that 

 minute organisms are studied, not on account of the intrin- 

 sic interest which attaches to their life-history as plants or 

 animals, but owing to the importance of their effects. 

 And, judged by the role which they play in the drama of 

 Life, these unicellular things, invisible to the naked eye, 

 have an importance far greater than that of the large and 

 conspicuous forms which until recently have monopolized 

 attention. Elephants and whales, oaks and eucalyptus, and 

 all other large animals and plants might disappear without 

 any great change in the habitableness of the globe ; whereas, 

 if bacteria and moulds were to cease to be, the surface of 

 the earth would become incapable of supporting life of any 

 kind. Were it not for these agents, which restore dead 

 plants and animals to the soil, leaves, as they fall, would 

 accumulate in a blanket impervious to the rootlets of ger- 

 minating seeds, and the bodies of animals would dry up 

 until, in the course of ages, they hid the ground from 

 the sun. 



Microphytology differs from other sciences, in as much as 

 it is studied not as a pure science, but for the sake of its 

 applications. As a pure science it would be a branch of 

 botany ; as applied science it belongs to medicine, as well 

 as to various industries. Of the greatest importance to the 

 human race is the discovery that the entrance of microbes 

 into the body is the true cause of many diseases, and these 

 the most inimical to life. Again, coming within the prov- 

 ince of public health, it is found that the destruction of 

 sewage is due to the same agents. Hence the science is 

 most ardently pursued by medical men. In commerce the 



