When materials began to accumulate they were detrimental to the polygenist theory. Especially was this the case with regard to the proof of what Broca termed “_eugenesis_”—_i.e._, that all the _Hominidæ_ are, and always have been, fertile with each other. This, which formed a test between species and varieties in Botany and Zoology, was claimed also in Anthropology, and the polygenists had to seek for support elsewhere. They found it in Linguistics; “language as a test of race” bulked large in ethnological controversy, and is not yet entirely extinct. At first the monogenists claimed language as supporting their views. All languages were to be traced to three sources—Indo-European, Semitic, and Malay; and these, in their turn, were the offspring of a parent tongue, now entirely lost. But it was soon found impossible to reconcile even Aryan and Semitic, and a common parent for all three languages was inconceivable. The linguistic argument then passed over to the polygenists. Hovelacque stated that “the ascertained impossibility of reducing a multiplicity of linguistic families to a common centre is for us sufficient proof of the original plurality of the races that have been developed with them.” M. Chavée[35] went further. “We might,” he says, “put Semitic children and Indo-European children apart, who had been taught by deaf mutes, and we should find that the former would naturally speak a Semitic language, the latter an Aryan language.” F. Müller and others took up this line of argument, holding that distinct stock languages proved the existence of distinct stock races. But, as Professor Keane points out, in his summary of the controversy (1896, chap. vii.), _quod nimis probat, nihil probat_—what proves too much, proves nothing—and the hundred or more stock languages in America alone, reduced the argument to an absurdity. Footnote 35: See Topinard, 1878, p. 424. [Sidenote: =Monogenists.=] Among the monogenists may be included most of the older anthropologists—Linnæus, Buffon, Blumenbach, Camper, Prichard, and Lawrence. Since they held that all mankind was descended from a single pair (the question as to whether this pair were white, black, or red, occasioned a further discussion), they had to account for the subsequent divergence producing the present clearly-recognised varieties; and, in so doing, anticipated the theory of evolution, which was not clearly enunciated until the time of Lamarck.