SECTION II 



THE ORGAXIC GROWTH OF THE LIVING WORLD 



For many years I have myself, from researches on the varia- 

 tion of single species of animals, especially with respect to 

 markings of colour, acquired and expressed ^ views upon 

 the ultimate causes of the origin of species. These views are 

 essentially in contradiction to those of Weismann, and to 

 those of Nageli, while in details they agree with those of each. 



The agreement consists in this, that I have from the 

 zoological standpoint, as already remarked, pointed out and 

 emphatically maintained that the variation of species takes 

 place not in all kinds of directions irregularly, but always in 

 definite directions, and indeed in each species in a given 

 time in only a few directions. 



Further, I opposed, as mentioned likewise in the Introduc- 



^ Th. Eimer, Zoologische Studien auf Capri, ii. Laccrta muralis coerulea, ein 

 Beitrag zur Danoinschen Lehre ; Leipzig, Engelmann, 1874. Untersuchungen uher 

 das Variiren der Mauereidechse, ein Beitrag zur Theorie von der Entvncklung aus 

 constitutionellen Ursachen; Archiv fur Naturgeschichte (and separately), Berlin, 

 Nicolai, 1881. Ueber den Begriff des thierischen Individuuvi, an Address 

 delivered at the second general meeting of the " Versammlung deutscher Natur- 

 forscher und Aerzte," at Freiburg i. B. , 1883. Further, ray articles: Ueber 

 die Zeichnimg der Thiere, in the Zoolog. Anzdger, 1882, 1883, 1884 ; and 

 (with figures) in the journal Huviboldt, 1885, 1886. Also Ueber die Zeich- 

 nung der Vogel und Sdugethiere, Lecture delivered at the meeting of the 

 "Verein fiir vaterlandische Naturkunde in Wiirttemberg " at Nagold, 1882, in 

 Wurttb. natunv. Jahreshefte, 1883. 



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