classification after another has been swept away in the 

 domain of organic nature ... the distinguishing charac- 

 teristics, which are almost becoming articles of faith, are 

 losing their absolute validity . . . ."° 



Baer's theory of types was more flexible than Cuvier's, 

 because Baer assumed, though very cautiously, that all 

 animals develop from one general original form, and, more 

 confidently, that there is variability of organisms within 

 the limits of each type. Although it is impossible to 

 consider Baer a consistent evolutionist, his services in 

 the preparation of the evolutionary idea are unquestionable. 



Engels further defined Baer's historical significance. 

 Remarking that the first assault on the theory of species 

 constancy and proclamation of evolution was accomplished 

 in 1759 by K. F. Wolff, Engels continued: "But what he had 

 was a genius' anticipation which took a defined form in Oken, 

 Lamarck and Baer, and was victoriously carried through by 

 Darwin in 1859, exactly one hundred years later. "9 In 

 another place, on enumerating the gaps opened by science, 

 Fngels wrote: "(Natural science, at the outset revolutionary, 

 was confronted by an out-and-out conservative nature) in 

 which everything remained today as it was at the beginning of 

 the world, and in which, right to the end of the world, 

 everything would remain as it had been at its beginning. "10 



The urge to find out the most essential in the processes 

 of individual form-production led Baer to establish the true 

 relationships in the organization of different animals; 



8. F. Engels, ANT I -DUHRINC , Gospolitiedat, p. 13, 1952. 

 (Ed.: English page numbers are from ANTT-Dt)HRING, Moscow? 

 Foreign Language Publishing House, 1959, p. 21.) 



9. F. Engels. DIALECTICS OF NATURE. Gospolitisdat, p. 11, 

 1952. (Ed.: English version page numbers are from 

 DIALECTICS OF NATURE, New York: International 

 Publications, 1940, ed. and trans, by Clemens Dutt, p. 13.) 



10. F. Engels. DIALECTICS OF NATURE, pp. 153-154 (186). 



351 



