PREFACE 
The writer is annually in receipt of letters from students, 
teachers, ministers, medical men, and others, asking for in- 
formation on topics in general biology, and for references to 
the best reading on that subject. The increasing frequency 
of such inquiries, and the wide range of topics covered, have 
created the impression that an untechnical account of the 
rise and progress of biology would be of interest to a con- 
siderable audience. As might be surmised, the references 
most commonly asked for are those relating to different 
phases of the Evolution Theory; but the fact is usually over- 
looked by the inquirers that some knowledge of other features 
of biological research is essential even to an intelligent com- 
prehension of that theory. 
In this sketch J have attempted to bring under one view 
the broad features of biological progress, and to increase the 
human interest by writing the story around the lives of the 
great Leaders. The practical execution of the task resolved 
" itself largely into the question of what to omit. The number 
of detailed researches upon which progress in biology rests 
made rigid selection necessary, and the difficulties of separat- 
ing the essential from the less important, and of distinguish- 
ing between men of temporary notoriety and those of endur- 
ing fame, have given rise to no small perplexitics. 
The aim has been kept in mind to give a picture sufh- 
ciently diagrammatic not to confuse the general reader, and 
it is hoped that the omissions which have seemed necessary 
will, in a measure, be compensated for by the clearness of 
the picture. References to selected books and articles have 
ate 
