206 Inheritance of Acquired Characters 
For if these structures had all arisen through nat- 
ural selection only, selecting the most fit from among all 
the chance variations, one could not explain how, in 
different species, even though they were subjected in 
respect to that particular organ to like mechanical con- 
ditions, it could lead to one and the same result. In 
fact how could one affirm that the structure of any given 
organ must be of one certain character only and no other, 
in order to render the species most fit for the struggle 
for existence? So mere chance must be invoked to 
account for the fact that of the numerous structures 
among which natural selection could choose, it has 
selected in the most different species subjected to the 
action of the same mechanical conditions in relation to 
only one of their organs, just one single structure for 
this organ, absolutely alike for all these different species. 
A similar phenomenon, which leads one toward the 
same view, is mentioned by DeVries, as already noted, 
in support of his theory of pangens or preformistic 
germs, representative of definite characters; namely, that 
the most diverse species of plants have often the power 
of producing a greater or less number of identical chem- 
ical compounds. “Insectivorous plants, for example, 
belong to the most different natural families, neverthe- 
less they all possess the faculty of producing from their 
leaves the necessary mixture of an enzyme and an acid 
requisite for dissolving albuminous bodies.” 157 Darwin 
himself has already remarked that this mixture is quite 
similar to the gastric juice of the higher animals. 
Now without wishing to touch anew upon the ques- 
tion of preformistic germs which we have already dis- 
*®71De Vries: Intracellulare Pangenesis. P. 8—10. 
