Linnæus believed in fixity of species, but had doubts about the Biblical account. As a naturalist, he found it difficult to credit the exceptional nature of a country which had supplied the wants of zoological species as opposed to one another as the polar bear and the tropical hippopotamus. Buffon ascribed the variations of man to the influence of climate and diet. Though Prichard and Lawrence both denied the possibility of the transmission of acquired characters, Prichard believed that the transmission of occasional variations might, to some extent, account for the diversities of races.[36] Lawrence wrote more clearly: “Racial differences can be explained only by two principles—namely, the occasional production of an offspring with different characters from those of the parents, as a native or congenital variety; and the propagation of such varieties by generation.” He considered that domestication favoured the production of these congenital and transmissible variations, and, anticipating the Eugenic school, deplored the fact that, while so much care and attention was paid to the breeding of domestic animals, the breeding of man was left to the vagaries of his own individual fancy. Footnote 36: In an essay entitled “A Remarkable Anticipation of Modern Views on Evolution,” Professor E. B. Poulton draws attention to the ideas expressed in the first and second editions of the _Researches_, by Prichard, “one of the most remarkable and clear-sighted of the predecessors of Darwin and Wallace.... It is an anomaly that such works as the _Vestiges_ should attract attention, while Prichard’s keen insight, sound judgment, and balanced reasoning on many aspects of organic evolution, and especially on the scope of heredity, should remain unknown.” _Essays on Evolution_, 1908, pp. 192, 175. [Sidenote: =Lawrence.=] Sir William Lawrence (1783-1867) was appointed Professor of Anatomy and Surgery to the Royal College of Surgeons at the early age of thirty-two. His lectures on “Comparative Anatomy, Physiology, Zoology, and the Natural History of Man,” delivered between 1816 and 1818, raised an immediate outcry; and the author (to use his own words) was charged “with the unworthy design of propagating opinions detrimental to society, and of endeavouring to enforce them for the purpose of loosening those restraints in which the welfare of mankind exists.” Lawrence was forced to bow before the storm of abuse, and announce publicly that the volumes had been suppressed, as he was refused copyright. It is interesting to note that these lectures are among those at present recommended for the use of students of Anthropology.