other physiological ideas. Vellanskii added to these 

 many, essentially unfounded, peculiarities of thought, which 

 he defended in a letter' to M. G, Pavlov soliciting comments 

 on his physiological lectures. 20 



Vellanskii presented his erabryological ideas in the 

 book, BIOLOGICAL INVESTIGATIONS, the thirteenth chapter 

 of which is "Birth and Death." For discussion of the natural 

 development of the individual which starts at birth and ends 

 at death, Vellanskii used the favorite principle of the 

 nature-philosophers, the principle of polarity. He gave 

 comparisons of opposing phenomena: "The moment of birth, in 

 essence, is the conception and development of the fetus in 

 the maternal uterus .... death begins with disease and ends 

 with decomposition. Therefore conception is equal to decompo- 

 sition, and development of the embryo corresponds to disease 

 of the formed organism. "21 



For understanding individual development, Vellanskii 

 considered it necessary to analyze the minute structure of 

 the formed organism, which he described in agreement with 

 Oken's ideas: "In order to see the process of birth and death 

 of certain organisms, it is necessary to look first at 

 complexes in organic nature, in which unity is confirmed and 

 its usual stability is found. This complex consists of 

 infusoria, which are formed by the decomposition of any 

 substance in water." 22 



Describing in detail the way to obtain a culture of 

 infusoria in an infusion of grass or meat, Vellanskii rejected 

 the possibility that these creatures develop from eggs: 



Infusoria in essence are the primary monads of the 

 organic world .... But the consideration of 

 these as preformed creatures which undergo aggregation 

 and thereby give rise to all animals and plants could 



20. This letter of May 29, 1834 is given in the book by 

 Kh. J. Koshtoyants, OUTLINE OF THE HISTORY OF 

 PHYSIOLOGY IN RUSSIA. 



21 . vellanskii, BIOLOGICAL INVESTIGATION, p. 402. 



22. Ibid., p. 403. 



153 



