Prevost found similar bodies in the reproductive organs of 

 snails and the cockle-shell, in which there is neither a 

 cephalic brain nor a spinal cord, then the authors 



were required to have oratorical art to explain 

 that they were incorrectly understood? they say 

 that they did not affirm that the narrow system 

 is directly formed from the testicular bodies 

 which penetrate into the ovum, and considered 

 that this penetration is necessary as a prepara- 

 tion to its formation. By this explanation, 

 however, they themselves frustrated their hypo- 

 thesis. (II, Id, pp. 12-13 (p. 6)) 



Next Baer strove to show that the task of explaining 

 the defined beginning of individual development will not be 

 solved if we assume the preexistence of future generations 

 in the bodies of the parents, because, in this case, we 

 must assume that all living creatures, right up to the last 

 generation, were created at the same time as the first 

 individuals. Consequently, in the chick ovary all the 

 chicks that are to be formed must be present, and in the 

 ovary of each one of them must be again all their future 

 offspring, and so on. These offspring included in each 

 other, because of their infinitely small sizes, are unavail- 

 able for observation by our optical facilities. Although 

 the hypothesis, as Baer said, is next to nonsense, never- 

 theless it was defended by many famous naturalists. This 

 represents a clear example of the confusion into which 

 one can fall if he bases opinions on suggestions and not on 

 observations. If this point of view were correct, then it 

 should have been recognized that inevitably the time would 

 come when all life on earth would end because all creation 

 had been already formulated. Continuing ironically this 

 "theoretical argument," which in part relies on religious 

 belief, Baer wrote that after the exhaustion of preformed 

 generations the Creator would then begin his work again, 

 since the first effort of creation appeared to be so 



3. J. L. Prevost, "On the Generation of Painters Mould," 

 ANN. SCI. NAT., 7 (1826), p. 447-455. 



369 



