instability." The article contains numerous examples of 

 anatomical variations in man. Wolff noted that not only 

 small venous branches whose variability is endless and is 

 not defined, not only large veins and arterial vessels, not 

 only nerves, but also bones, muscles and the internal 

 organs are characterized by instability. This is related, 

 according to Wolff, even to the "most precious parts of 

 the body as the heart and brain to the extent that it is 

 hardly possible to find even two human bodies in which these 

 precious internal organs are identical in their form, 

 situation and proportions" (p. 217 - 218], The variability 

 of organs in the adults depends on their more distinctly 

 expressed variability in the embryonic period. For the 

 illustration he referred to the fact of the deep differences 

 in the structure of the chick embryos, which "are sometimes 

 so unequal that they could have been mistaken as other 

 animals if it was not known that they had been taken from 

 chicken eggs" (p. 223). 



Wolff's epigenetic ideas, which he based on study of 

 ontogenetic development and on variability in individual 

 development, should certainly have led Wolff to question the 

 origin of diversity of organic forms, i.e. to the problem 

 of evolution in the modern understanding of this word. 

 Actually, if development is a new-formation and not growth 

 from the beginning of existence; the variability of creatures 

 could not be primordial, could not be a sequence of a creative 

 action. In the published reports Wolff did not consider this 

 question himself; however, the significance of the principle 

 of epigenesis did not escape Engels' insight into the problems 

 of species evolution. In DIALECTICS OF NATURE the 

 following very significant paragraphs were dedicated to 

 Wolff: "... K. Wolff produced in 1759 the first attack on 



7. Wolff, "De inconstantia fabricae corporis humani , 



de eligendisque ad earn representandum exemplaribus , " 

 ACTA ACAD. SCIENT. PETROP . pro anno 1778 (1781), 

 pp. 217 - 235. The judgment about this subject can also 

 be found in others of Wolff's anatomical works (see list 

 in Wolffs THEORY OF CONCEPTION, Academy of Science 

 USSR, 1950, pp. 478 - 480). 



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