Biology, General And Medical

PREFACE TO THE SECOND EDITION. THE cordial reception and favorable criticism accorded the first edition of this little book, prompted its author to exert every effort to eliminate such defects as were discovered by his reviewers, to accept the kindly sugges- tions of several of his readers, and, without considerably increasing its size, to introduce such new matter as would bring its contents up to date and increase its use- fulness. It is hoped that all this has been accomplished, and that future readers may find the book a reliable guide in the much-neglected field of biological science that borders upon and often overlaps the Institutes of Medicine. PHILADELPHIA, PA., November, 1913. 11 JOSEPH MCFAKLAND. PREFACE. IN preparing this book it has been the purpose of the author to acquaint his readers with the peculiar nature and interesting reactions of Living Substance to help him trace it to its probable, thoughunknown, beginnings and follow it through its multifarious differentiations to its highest complexity. In so far as this has been accomplished, the work is a General Biology. But more has been attempted, for the problems have been so considered as to show that man is no separate entity, apart from the general world of living things, but is a unit in the general scheme of things and subject to the same laws that apply throughout the universe. Inasmuch as many of the subjects treated are of importance to students contemplating future medical studies, and inasmuch as all of them are of interest and importance to students of medicine and physicians the work may, with justification, claim to be a Medical Biology. All of the problems of medical science are in a sense biological, andmany of the problems of biological science medical. Medical science is, in fact, a branch of biology and should be studied as such. Each chapter treats of some subject or subjects upon which the pen would gladly linger and upon which a volume might be written, and professional biologists will, no doubt, be disappointed at the brief treatment their pet theories receive as well as astonished at the space devoted to other, and to them less important, . matters, but this is the inevitable result of the particular of view of the author. point Nearly all of the subjects treated are of controversial nature, but that is the present state of biological science. Attempts to crystallize incomplete information into laws lead to theory rather than to fact, and the subject passes from theory to theory in search of the fact...