The Theory of Evolution 45 
nent in this connection, yet the theory has claimed an ever 
increasing number of adherents, until at the present time it 
is rare to find a biologist who does not accept in one form or 
another the general principle involved in the theory. The 
storm of criticism aroused by the publication of Darwin’s 
“Origin of Species,” was directed more against the doctrine 
of evolution than against Darwin’s argument for natural se- 
lection. The ground has been gone over so often that there 
would be little interest in going over it again. It will be more 
profitable to turn our attention to the latest attack on the 
theory from the ranks of the zoologists themselves. 
Fleischmann, in his recent book, “‘ Die Descendenztheorie,” 
has made a new assault on the theory of evolution from the 
three standpoints of paleontology, comparative anatomy, and 
embryology. His general method is to try to show that the 
recognized leaders in these different branches of biology 
have been led to express essentially different views on 
the same questions, or rather have compromised the doc- 
trine by the examples they have given to illustrate it. 
Fleischmann is fond of bringing together the antiquated 
and generally exaggerated views of writers like Haeckel, 
and contrasting them with more recent views on the same 
subject, without making sufficient allowances for the ad- 
vances in knowledge that have taken place. He selects 
from each field a few specific examples, by means of 
which he illustrates the weakness, and even, as he be- 
lieves, the falsity of the deductions drawn for the par- 
ticular case. For example, the plan of structure of the 
vertebrates is dealt with in the following way: In this 
group the limbs, consisting typically of a pair of fore- 
legs and a pair of hind-legs, appear under the form of 
cylindrical outgrowths of the body. In the salamander, 
in the turtle, in the dog, the cylindrical legs, supporting 
the body and serving to support it above the ground, are 
used also for progression. The general purpose to which 
