_Contradictions in the New Theory._—Moreover, these mistakes involve those who make them in a series of inextricable contradictions. Here, for example, is life; it is found, they say, in three forms:—Life manifested, or condition 1º; latent life, or condition 3º. So far this is the classical theory; but they add a condition 2º, which is what might be called _pathological or incomplete life_. This is defined by the following characteristic:—That its functional phenomena are identical with those in the first form, but that they are not accompanied by assimilation and by protoplasmic growth, But since, they say, growth is the chemical consequence of the functional activity, since it is so to speak its metabolic aspect, since it is confused with it, and inseparable from it, by the argument—then it is contradictory and logically absurd to speak of condition 2º. It would be acknowledging in the case of the anucleated merozoite, for example, a functional activity unaccompanied by assimilation, yet identical with the functional activity which is accompanied by assimilation in the nucleated merozoite. The general movement, that of the cilia, the taking of food, the evacuation of the fæces, the contraction of the pulsatile vacuoles, are the same. And this fact is the best proof that this vital functional activity (with the organic destruction which is its energetic source) must be distinguished from the assimilation which usually follows it, and which in exceptional cases may not follow it. We shall carry this discussion no farther. We have examined at some length Le Dantec’s views, and we have contrasted them with the doctrine which has been current in general physiology since the time of Claude Bernard, and this comparison does not turn out quite to their advantage. It was inevitable that the experimental and realistic spirit which inspired the doctrine of the celebrated physiologist made his work really too systematic. His formula, “life is death,” and the form he gave his ideas, are not always irreproachably correct. They lend themselves at times to criticism. Sometimes they require commentary. These are errors of detail which Le Dantec has summarized somewhat roughly. There is no necessity to do this in his own case. We pay our tribute to the clearness of his language, although we believe the foundations of his system are false and ill-founded. Their rigour is purely verbal. Their external qualities, their careful arrangement are well adapted to the seduction of the systematic mind prepared by mathematical teaching. This new theory of life is presented with pedagogic talent of the highest order. We think we have shown that the foundations are entirely fallacious, in particular the following:—Vital condition No. 2º; the confusion between functional activity and assimilating synthesis; the so-called absolute connection between morphogeny and chemical composition; the fundamental distinction between elementary life and individual life.