X1V PREFACE. 
the “Naturliche Schépfungsgeschichte” in Germany. This 
book took its origin in the shorthand notes of a course of 
lectures which treated, before a mixed audience and in 
a popular form, the most important topics discussed in the 
“Generelle Morphologie.” The notes were subsequently 
revised, and received considerable additions. The book 
appeared first in 1868, its fourth edition in 1873, and has 
been translated into several languages. I hope that it may 
also find sympathy in the fatherland of Darwin, the more so 
since it contains special morphological evidence in favour of 
many of the important doctrines with which this greatest 
naturalist of our century has enriched science. Proud as 
England may be to be called the fatherland of Newton, who, 
with his law of gravitation, brought inorganic nature under 
the dominion of natural laws of cause and effect, yet may 
she with even greater pride reckon Charles Darwin among 
her sons—he who solved the yet harder problem of bring- 
ing the complicated phenomena of organic nature under the 
sway of the same natural laws. 
The reproach which is now oftenest made against the 
Descent Theory is that it is not securely founded, not suffi- 
ciently proven. Not only its distinct opponents maintain that 
there is a want of satisfactory proofs, but even faint-hearted 
and wavering adherents declare that Darwin’s hypothesis is 
still wanting fundamental proof. Neither the former nor the 
latter estimate rightly the immeasurable weight which the 
great series of phenomena of comparative anatomy and onto- 
geny, paleontology and taxonomy, chorology and cecology, 
cast into the scale in favour of the doctrine of filiation. 
Darwin’s Theory of Selection, which completely explains the 
origin of species through the combined action of Inheritance 
