Now although, as Weismann goes on to observe, “in these lower plants, the separation between somatic and reproductive cells is slight,” in the facts to which he alludes we appear to have good evidence of an influence exercised by somatic cells upon the germinal contents of reproductive cells. And if such an influence is capable of being exercised in the case of “these lower plants,” it follows that there is no such _absolute_ separation between somatic tissues and germ-plasm as Weismann’s theory requires. Moreover it follows that, if the essential distinction between germ-plasm and somato-plasm (or “somatic idio-plasm”) is thus violated at the very foundation of the multicellular organisms, there ceases to be any _a priori_ reason for drawing arbitrary limits, either as to the level of organization at which such “transmission of somatogenetic variation has occurred,” or as to the degree of detail into which it may extend. Both these matters then stand to be tested by observation; and the burden of proof lies with the school of Weismann to show at what level of organization, and at what degree of representation, somatogenetic changes cease to reproduce themselves by heredity. Passing on, then, to higher levels of organization, and therefore to higher degrees of representation, I shall endeavour to show that this burden of proof cannot be discharged. For I shall endeavour to show, not merely, as just shown, that there ceases to be any _a priori_ reason for drawing arbitrary limits with respect either to levels of organization or to degrees of representation, but that, as a matter of fact, there are no such limits as the passage above quoted assigns. On the contrary, I believe there is as good evidence to prove the not unfrequent transmission of acquired (“somatogenetic”) characters among the higher plants—and even among the higher animals—as there is of the occurrence of this phenomenon in the case of the Alga just mentioned. But in order to do this evidence justice, I shall have to take a new point of departure and consider as a separate question the transmissibility of acquired characters. Meanwhile, and as far as Weismann’s theory of heredity is concerned, it is enough to have shown,—if I have been successful in doing so,—that not only is there no evidence to sustain his fundamental postulate touching the material of heredity having always occupied a separate “sphere” of its own “since the first origin of life”; but that there is good evidence to prove the contrary. For whether or not the reciprocal action of “somato-plasm” and “germ-plasm” can ever proceed to the extent of causing acquired characters to be inherited (so as to produce “representative congenital changes”), all that is distinctive in this theory must be regarded as barren speculation, unless it can be shown that the foregoing facts have failed to prove such a reciprocal action as ever occurring in any lower degree (so as to produce “specialized congenital changes”).