This tracing of genealogies is doubtless the most spectacular feature of the new zoology, yet it must be clear that the establishment of lines of evolution is at best merely a preparation for the all-important question, Why have these creatures, man included, evolved at all? That question goes to the heart of the new zoological philosophy. A partial answer was, of course, given by Darwin in his great doctrine of natural selection. But this doctrine, while explaining the preservation of favorable variations, made no attempt to account for the variations themselves. Professor Haeckel's contribution to the subject consisted in the revival of the doctrine of Lamarck, that individual variations, in response to environmental influences, are transmitted to the offspring, and thus furnish the material upon which, applying Darwin's principle, evolution may proceed. This Lamarck-Haeckel doctrine was under a cloud for a recent decade, during the brief passing of the Weismannian myth, but it has now emerged, and stands as the one recognized factor in the origin of those variations whose cumulative preservation through natural selection has resulted in the evolution of organic forms.
But may there not be other factors, as yet unrecognized, that supplement the Lamarckian and Darwinian principles in bringing about this marvellous evolution of beings? That, it would seem, is the most vital question that the philosophical zoology of our generation must hand on to the twentieth century. For today not even Professor Haeckel himself can give it answer.
VII. SOME MEDICAL LABORATORIES AND MEDICAL PROBLEMS
THE national egotism that characterizes the French mind is not without its compensations. It leads, for example, to the tangible recognition of the merits of the great men of the nation and to the promulgation of their names in many public ways. Thus it would be hard to mention a truly distinguished Frenchman of the older generations whose name has not been given to a street in Paris. Of the men of science thus honored, one recalls off-hand the names of Buffon, Cuvier, Geoffroy Saint-Hilaire, Pinel, Esquirol, Lamarck, Laplace, Lavoisier, Arago, Claude Bernard, Broca--indeed, one could readily extend the list to tiresome dimensions. Moreover, it is a list that is periodically increased by the addition of new names, as occasion offers, for the Parisian authorities never hesitate to rechristen a street or a portion of a street, regardless of former associations.
