6 BIOLOGY AND ITS MAKERS 
the idea of evolution permeates the whole. It will be neces- 
sary to consider the advances in these fields separately, and 
to indicate the union of the results into the main channel of 
progress. Secondly, in attempting to trace the growth of ideas 
in this department of learning one sees that there has been 
acontinuity of development. The growth of these notions 
has not been that of a chaotic assemblage of ideas, but a 
well-connected story in which the new is built upon the old 
in orderly succession. The old ideas have not been com- 
pletely superseded by the new, but they have been molded 
into new forms to keep pace with the advance of investigation. 
In its early phases, the growth of biology was slow and dis- 
cursive, but from the time of Linneus to Darwin, although 
the details were greatly multiplied, there has been a relatively 
simple and orderly progress. 
Facts and Ideas.—There are many books about biology, 
with directions for laboratory observation and experiment, 
and also many of the leading facts of the science have been 
given to the public, but an account of the growth of the ideas, 
which are interpretations of the facts, has been rarely at- 
tempted. From the books referred to, it is almost impossible 
to get an idea of biology asa unit; this even the students in 
our universities acquire only through a coherent presentation 
of the subject in the classroom, on the basis of their work in 
the laboratory. The critical training in the laboratory is 
most important, but, after all, it is only a part, although an 
essential part, of a knowledge of biology. In general, too 
little attention is paid to interpretations and the drill is con- 
fined to a few facts. Now, the facts are related to the ideas 
of the science as statistics to history—meaningless without 
interpretation. In the rise of biology the facts have accu- 
mulated constantly, through observation and experiment, but 
the gencral truths have emerged slowly and _ periodically, 
whenever there has been granted to some mind an insight 
