248 Theories Treating of Inheritance 



the organism upon another; so also the morphological 

 changes in animal ontogeny arise in the same way 

 through manifold inductive stimuli "Inductionsreize" 

 which are almost always of internal origin." 188 



This conception, especially if it is extended to the 

 whole process of development in general, would really 

 amount to a reduction of ontogeny, exactly as in the plant 

 formations above mentioned in which external agents act 

 as true formative stimuli, almost to a phylogeny, con- 

 stantly repeating itself anew in each generation. And 

 the fact that successively arising generations would in 

 spite of that remain always alike is to be attributed to the 

 repetition, proceeding always in the same way, of succes- 

 sive functional stimuli both without and within the 

 organism in process of development, which are produced 

 gradually one out of the other through the principle of 

 fructifying causality and give rise each time to these new 

 phylogeneses. 



In this respect the conception of Herbst recalls the 

 purely mechanical explanation of development given by 

 His, who refers the appearance of the same ontogenetic 

 phenomena every time to the repetition of definite me- 

 chanical influences, proceeding always in the same way. 

 Since each influence, itself induced by the influences 

 preceding it, induces in its turn the influences following 

 it, then if only the first link of the chain is constantly 

 repeated in the same way in each generation, that would 

 be enough to cause the same thing to happen in the case 

 of all the others. 



188 Herbst: t)ber die Bedeutung der Reizphysiologie fur die 

 kausale Auffassung von Vorgangen in der tierischen Ontogenese. 

 Biol. Centralbl. 1894. Bd. XIV. No. 1822. P. 771 ; and Bd. XV, 

 N. 2024. P- 8 5 2 - 



