196 - THE AMERICAN NATURALIST.  [Vol. XXXIII. 
material distinct from the cell sap, to which he gave the name 
protoplasm. This was in 1846, but even before this Dujardin, 
in 1835, had described what he termed the savcode in the Foram- 
inifera. Schulze much later identified these two substances 
and modified the original cell theory by making a mass of proto- 
plasm, independent of any special bounding wall, such as the 
word ce// implies, the unit of structure. He converted Bichat’s 
tissue elements into aggregates of protoplasmic elements, and, 
by extending his generalization to plants, made possible Hux- 
‘ley’s characterization of protoplasm as the “physical basis of 
life.’ 
All these discoveries and hypotheses were contributing to 
prepare the mind of the scientific world for the reawakening 
of the doctrine of evolution. The theological bias and the 
influence of Cuvier were still powerful at the middle of the 
century, but they could not withstand the march of observation 
and deduction which was tending surely to the overthrow of the 
Type theory, a result accomplished by the publication of Dar- 
win’s Origin of Species in 1859. Darwin’s generalizations and 
the resulting acceptance of the theory of evolution at once 
placed anatomy in a new position. It could no longer be held 
aloof from the other biological sciences. Man is not an organ- 
ism entirely distinct from all others; he is merely the culmina- 
tion of one line of evolution. His structural peculiarities are 
not minute details of a primary immutable plan, but are to be 
explained by reference to his past history. Departures from 
the typical conditions, so frequent and in many cases so remark- 
able, are not mere vagaries without significance, but are remin- 
iscences of previous conditions or indications of developmental 
possibilities frequently brought to completion in other forms. 
The doctrine of evolution is the “one increasing purpose ” 
whose influence is traceable throughout all science, and it has 
consequently broadened all our views by bringing the various 
departments of research into interdependence with one another. 
This is the age of specialties, and necessarily so, since the 
volume of knowledge has grown too great for one finite mind 
to comprehend the whole; but now, more than ever before, 
-there is necessity for correlation. Each department of science 
