ANTICIPATION AND INTERPRETATION 37 



types, was also dimly perceived by Aristotle, but 

 not, of course, in its vital relation to Evolution. 



Aristotle also distinguished between living and 

 lifeless matter as the organic and inorganic, but 

 in common with all the Greeks and, in fact, with 

 all zoologists up to comparatively recent times, 

 he believed in abiogenesis, or the spontaneous de- 

 velopment of living from lifeless matter. This be- 

 lief was handed down through all the Middle 

 Ages, and appeared in its crudest form as an ex- 

 planation, not only of the origin of the lowest 

 forms of life, but of the higher forms, even as 

 late as the beginning of the nineteenth century. 

 As a spurious natui-alistic explanation it was one 

 of the greatest impediments to the growth of the 

 true evolution idea. 



The law of biogenesis, or of life from life, was 

 clearly stated in Harvey's famous and oft-quoted 

 dictum, omne vivum eoo ovo, but was not finally 

 demonstrated until quite late in the nineteenth 

 century. The belief in spontaneous or direct 

 origin from the earth, even of the higher orga- 

 nisms like man, thus began amongst the Greeks 

 as an explanation of the origin of man and of the 

 highest forms of life ; it was gradually contracted 

 to the origin of the lower and smaller forms of 

 life and, finally, to the lowest invisible forms of 

 bacteria, until, as an outcome of the discussions, 

 which are still fresh in our memory, between 



