446 GENERAL ZOOLOGY 



nature and by experiment, — he brought about a complete 

 change of attitude toward the nature of truth. Authority, 

 except when it depends upon facts obtainable by any other 

 searcher after truth, has no place in science. Our whole 

 development of laboratory science and research resulted 

 from the application of Bacon's principles of philosophy. 



Spontaneous Generation of Life. The origin of life has 

 been a problem on which man has speculated since his 

 earliest history. Until fairly recently it was commonly be- 

 lieved that living animals are being continuously formed 

 out of lifeless matter. By simple observation men witnessed 

 that cheese placed in a cupboard seemed to turn into mice. 

 Further, when meat was allowed to stand in the open, it 

 soon gave rise to blowflies. Such observations were com- 

 mon enough and unchallenged by most persons. At that 

 time no one understood how mice develop or how flies 

 come only from eggs. In fact, the idea that lifeless matter 

 could turn into living beings was not finally disproved 

 until the time of Pasteur. About 1860 Pasteur performed 

 experiments which proved that even the simplest organisms 

 are developed only from other living beings of their own 



kind. 



Zoology in America. Various agencies have contributed 

 to the advance of zoology in America. One of the most out- 

 standing of these has been the support accorded to zoolog- 

 ical research through federal and state funds. Our federal 

 government from an early date has recognized the service 

 of science to humanity. Through its Bureaus of Entomol- 

 ogy, Fisheries, Animal Industry, and Biological Survey 

 many economic problems have been solved. These bureaus 

 have not confined their attention to the control of destruc- 

 tive or harmful animals. A program of researches in pure 

 science has been carried out by all these bureaus in addition 

 to their programs of economic work. Frequently the re- 



