Inheritance in Unicellular Forms 209 
paleontology has demonstrated in so splendid a manner, 
of the gradual modification of certain parts through long 
geologic ages toward ideals of mechanical perfection, 
for example, of the gradual perfecting of the skeletal 
articulations? Not only does the post-Darwinian school 
afford no explanation of this but with the acceptance of 
its theories this progress is indeed impossible.” 15° 
And Osborn’s view is similar. “Living matter,” 
writes he, “is characterized by a capacity of adaptive or 
purposeful reaction. If this capacity is inherited in the 
Protozoa, thanks to the simplicity of their process of 
propagation, it must be the same in the Metazoa. For 
each newly developed metazoon which retains the advan- 
tage of the inheritance of the adaptive reaction would 
be preserved, while each individual which loses this would 
degenerate. The mechanism of the inheritance of onto- 
genic adaptation must then have been developed in 
passing from the unicellular to the pluricellular forms 
by means of natural selection.” °° 
Weismann it seems to us could reply only by saying 
that natural selection may not have established the inher- 
itance of acquired characters in the pluricellular forms 
also, because the production of the mechanism neces- 
sary for that purpose had become materially impossible 
by reason of the structure of the metazoic organism. 
But this assertion, which would limit the capacities of 
living organic substance, must appear a little too hazard- 
158Cope: The mechanical Causes of the Development of the hard 
Parts of the Mammalia. Journ. of Marph., vol. VIII, No. 2, Boston, 
U. S. A. Ginn, Sept. 1889. P. 140—141. 
282Ocshorn: Alte und neue Probleme der Phylogenese. Ergebnisse 
der Anatomie und Entwicklungsgeschichte, herausgegeben von Mer- 
kel und Bonnet. Band. III. 1893. Wiesbaden, Bergmann, 1894, 
P. 607. 
