But another topic is even more clear in the theory of inheritance, as stated in Hering’s and Semon’s writings. The hypothetical fact that so-called “acquired characters” are inherited is undoubtedly the chief assumption of that theory. Indeed, it would be difficult to understand the advantage of the ambiguous word memory, had it not to call attention to the hypothetic fact that the organism possesses the faculty of “remembering” what once has happened to it or what it once has “done,” so to speak, and profiting by this remembering in the next generation. The zoologist Pauly indeed has stated this view of the matter in very distinct and clear terms. As we soon shall have another occasion to deal with the much-discussed problem of the “inheritance of acquired characters,” we at present need only say a few words about the “memory-theory” as a supposed “explanation” of heredity. Undoubtedly this theory postulates, either avowedly or by half-unconscious implication, that all the single processes in individual morphogenesis are the outcome either of adaptations of the morphological type, which happened to be necessary in some former generation, or of so-called contingent “variations,” of some sort or other, which also happened once in the ancestral line. Such a postulate, of course, is identical with what is generally called the theory of descent in any of its different forms. This theory is to occupy us in the next lectures; at present we only analyse the “memory-theory” as a theory of heredity in itself. In any case, to regard memory as the leading point in inheritance, at least if it is to signify what is called memory in any system of psychology, would be to postulate that either adaptation or contingent “variation” has been the origin of every morphogenetic process. Indeed, the American physiologist Jennings did not hesitate to defend such a view most strongly, and many others seem to be inclined to do the same. But such an assumption most certainly cannot be true. It cannot be true, because there are many phenomena in morphogenesis, notably all the phenomena akin to restitution of form, which occur in absolute perfection even the very first time they happen. These processes, for the simple reason of their *primary perfection*, cannot be due either to “learning” from a single adaptation, or to accidental variation. We shall afterwards employ a similar kind of argument to refute certain theories of evolution. It therefore may be of a certain logical interest to notice that at present, combating the memory-theory of inheritance, and hereafter, combating certain theories of descent, we select not “adaptation” or “variation” as the central points to be refuted, but the assumed *contingency* of both of them.