exact mode in which heredity operates, he finds himself confronted with a perfect jungle of divergent opinion. Recent biological writing on these subjects has served to clarify the issues at stake, but the household of organic science is still far from being at peace with itself.
The striking book before us affords an interesting and representative exposition of a tendency which has been regaining in scientific repute a position that for a generation past has often been denied it. Indeed, the extremer advocates of physico-chemical biology et id omne genus still view it with undisguised contempt. The tendency referred to involves the introduction of consciousness as a factor of fundamental moment in the explanation of genetic phenomena. So important is the rôle which Mr. Baldwin seems disposed to assign it, that it promises to furnish a means through which the most radical differences of Darwinian and Lamarckian may be converted into amicable harmony provided, of course, that the Lamarckian is willing, for it must be confessed that he is harmonized largely by absorption, a process he may resent.
Moreover, Mr. Baldwin's book offers another significant exemplification of current biological conditions in its extensive drafts upon philosophy. To many a scientific man it must seem an evil day when the fair raiment of science is disfigured with the tawdry pretensions of metaphysics. For better or for worse, however, biology appears to be entering upon a period of fresh synthetic effort, and all thorough-going synthesis is doomed to a measure of invasion by the philosophy of its own day. We shall make the grounds of this fact clearer as it bears on the present case a little further on.
The cardinal tenet in Mr. Baldwin's evolutionary creed,—a creed which is largely shared, be it said, both in content and originality of formulation by Messrs. Lloyd Morgan and Osborn,—may be put thus: By a process of preservative individual accommodation involving consciousness, single organisms keep themselves alive in times of danger, and thus secure the accumulation in successive generations of the variations which they may chance to represent. In this way useful structures and functions, e.g., instincts, gain time to mature, even though during the period of their development they may not have been useful. Through the destruction by natural selection of all harmful variations, the resulting effects would have at first sight all the appearance of a 'use-inheritance' origin of Lamarckian type, whereas, in point of fact, there may have been no real transmission of acquired characteristics at all. The important group of social and gregarious influences (imitation, tradition, etc.), by means of which
