ON THE GENETIC VIEW OF NATURE. 



321 



and plausible enough, but there remained the last strong- 

 hold of the older view, the existence of definite forms of 

 animal and vegetable life. Were these to be merely classi- 

 fied and reduced to separate types, as the morphological 

 view was contented to reduce them, or was the growing 

 evidence of variability to be interpreted in favour of a 

 gradual development of the higher out of the lower and 

 simpler forms of life ? Above all, how was the highest 

 type of all, man himself, to be regarded in such a com- 

 prehensive scheme of development ? In Germany many 20. 



J Genetic view 



great naturalists l were quite prepared for a consistent j^p*^ 

 genetic or developmental view of nature ; in France at 

 that time the question .was not agitated at all, the sug- 

 gestive writings of Lamarck and St Hilaire having been 



1 This does not refer to the 

 earlier writings of Goethe, Oken, 

 Treviranus, and others, whose 

 merits, since the appearance of 

 the ' Origin of Species,' have been 

 variously estimated by Huxley in 

 England and by Haeckel in Ger- 

 many : their speculations had, with 

 the generalisations of the 'Natur- 

 philosophie,' been swept away by 

 the inductive school represented in 

 botany at that time by von Mohl, 

 Nageli, and Hofmeister; in zoology 

 by the embryological school with 

 von Baer at its head. Of W. Hof- 

 meister (1824-1877), whose labours 

 begin about ten years before the 

 appearance of Darwin's great work, 

 Julius Sachs says : " The results of 

 his ' Comparative Researches ' (1849 

 and 1851) were magnificent beyond 

 all that has been achieved before or 

 since in the domain of descriptive 

 botany, . . . the conception of what 

 was meant by the development of 

 a plant was completely changed, 

 . . . the reader was presented with 



VOL. II. 



a picture of the genetic connection 

 between cryptogams and phanero- 

 gams which could not be reconciled 

 with the then reigning belief in the 

 constancy of species. . . . When, 

 eight years after Hofmeister's 

 ' Comparative Researches,' Dar- 

 win's theory of descent appeared, 

 the affinities of the large divisions 

 of the plant-world lay so openly, so 

 deeply founded, and so clearly be- 

 fore the eyes of students of nature, 

 that that theory had only to recog- 

 nise what had been made evident 

 in this line by genetic morph- 

 ology " (' Gesch. d. Botanik,' p. 215, 

 &c.) In another direction Nageli, 

 by his mechanical theory of " the 

 growth and internal structure of 

 organisms," which he reduces to 

 " physical, chemical, and mechanical 

 processes" (1860), fell in with Dar- 

 win's attempt to " reduce the earlier 

 purely formal consideration of or- 

 ganic structures to a causal (genetic) 

 view" (ibid., p. 373). 



