382 A SHORT HISTORY OF SCIENCE 



only of the higher animals. Omne vivum ex vivo was that of those 

 who held that living things come only from antecedent life, even 

 if not from eggs. Both of these groups were biogenesists, since 

 they maintained that living things come only from other living 

 things. Opposed to them were the abiogenesists who disputed 

 these ideas and believed in "spontaneous" generation (abiogenesis), 

 i.e. in the origin of living things from lifeless or non-living matter. 



The dispute was very old, Aristotle, for example, having 

 favored the idea of spontaneous generation. In the eighteenth 

 century Spallanzani for biogenesis and Needham for abiogenesis 

 had fought over again the ancient battle. Lamarck, at the be- 

 ginning of the nineteenth century, looked with favor upon abio- 

 genesis. The improved microscope of that century seemed at 

 first to strengthen the evidence for spontaneous generation by 

 revealing almost everywhere the presence of microbic life, and 

 the idea of an apparently easy generation of new life was wel- 

 comed by some interested in evolution, as accounting naturally 

 rather than supernaturally for the origin of life in general. Mean- 

 time, the discovery of the mammalian ovum by von Baer in 1827 

 had somewhat improved the position of the biogenesists, but the 

 whole question remained open and unsettled at the middle of 

 the century and until it was attacked by Pasteur, who was thor- 

 oughly equipped with the most exact scientific methods of the 

 day. For the details of the struggle in which Pasteur battled for 

 biogenesis we must refer the reader to the Life of Pasteur, by 

 Radot, and to Tyndall's Floating Matter of the Air. The up- 

 shot was that all the evidence advanced by the advocates of 

 spontaneous generation was shown by Pasteur, ably seconded 

 by Tyndall, to be due to defective technique ; for when such 

 defects were corrected no evidence remained of the generation 

 of life by lifeless matter. Thus was triumphantly closed, at least 

 for the time, one of the most ancient of controversies. 



Obviously, the question of a possible spontaneous generation 

 of living matter from lifeless under special conditions such as 

 may have existed during the early history of our globe remains 

 open. All that modern science has done is to controvert such 



