epigenesis as Wolff conceived it was unacceptable for 

 nature-philosophers because, according to the principles of 

 Naturphilosophie, no organic body develops; rather it presents 

 only a modification of previously existing living bodies. 



A necessary constituent of Naturphilosophie is the idea 

 of spontaneous generation, which nature-philosophers discussed 

 metaphysically and idealistically. Their discussions were not 

 about the development of the living from the non-living, i.e. 

 not about the progressive development of the material, but 

 about the continuous transformation of animated material — of 

 the unchanged organic monads, which are different organic 

 bodies and which exist primordially. 



That this particular understanding of spontaneous 

 generation was characteristic for Vellanskii is seen in 

 his following statements: 



Generation from undifferentiated creatures (generatio 

 aequivoca) must be the beginning in the origin of 

 organic creatures and characteristic for the lower 

 types of animals and plants. These include, in essence: 

 helminths, which originate and live in the interiors 

 of animal bodies; worms originating from decomposing 

 substances ; and some insects which originate in the 

 skin of a living body, such as crab lice, lice, 

 ulcerative acarus (Acarus exulcerans) . Originating 

 in other substances at a special temperature and 

 humidity, there are: fleas, some types of flies, 

 mosquitoes, and many others. All these originate 

 directly from specific organic monads, which are 

 everywhere present and ready. The intestinal helminths 

 do not find food or drink in the interiors in which 

 they live, but they are conceived from infusoria which 

 are present in the intestinal juice. Their worm shape 

 corresponds to the structure of the intestines 

 themselves; there are three types of helminths in 

 man: round, which correspond to the small intestine; 

 flat, the large intestines; and small worms, the 

 rectum .... Therefore lice generate a disease 

 called phthyriasis; and crab lice are frequently 

 found in pimples of the skin which no outside eggs 

 can penetrate. 25 



25. Ibid ., pp. 407 - 408. 



155 



