ON THE GENETIC VIEW OF NATURE. 299 



tion and replace it by the correcter doctrine of epigenesis 

 i.e., of repeated or after-formation. Haller 1 thought 

 very highly of this attack on his own view, but was 

 not convinced by it ; and although in botany Wolff's 

 views on the cellular structure of plants were adopted 

 in France by Mirbel, and those on metamorphosis were 

 unknowingly reproduced by Goethe, his influence on em- 

 bryology dates actually only from the year 1812, when 

 Meckel translated one of his treatises and thus drew 

 attention to his great merits. Wolff tried to refute the 

 theory of evolution or pre-formation, supplanting it by 

 that of epigenesis or after -formation, through actual 

 observations of the development of germs in plants and 

 animals in definite instances. In botany his views, 

 after lying dormant for a long period, led ultimately to 

 the famous cellular theory of Schleiden and Mohl. In 

 zoology, shortly after Meckel's republication of his treatise 

 in 1812, there were published the researches of Pander, 

 who, in his treatise on the development of the chick, 

 " gave a fuller and more exact view of the phenomena 

 less clearly indicated by Wolff, and laid the foundation 

 of the views of all subsequent embryologists." ' 



Pander was a Russian by birth, and so was his greater pander'an 

 contemporary and friend, Karl Ernst von Baer, 3 a man Baer. 



1 As Prof. J. Arthur Thomson known and unrecognised outside 



says ( ; Science of Life,' p. 120), "A j of Germany. Huxley made him 



single sentence, ' Es gibt kein '< known in this country by trans- 



Werden there is no Becoming,' lating extracts from his principal 



sufficiently indicates Haller's posi- 



writings for Taylor's ' Scientific 



tion." j Memoirs' in 1853, nearly thirty 



J. A. Thomson in article " Em- [ years after von Baer had begun the 



bryology "(' Ency. Brit.,' 9th ed., ! brilliant series of his researches. It 



p. 165). I can be said of him that he, even 



3 The work of von Baer (1792- I more than his forerunners, Pander 



1876) remained for a long time un- ! and Dbllinger, withdrew natural 



