Memoir on the Gorilla (Troglodytes Gorilla, Savage).

This reset monograph version of Owen's paper consists of revised and augmented portions of Owen's "Contributions to the natural history of the Anthropoid Apes," which appeared in the Transactions of the Zoological Society of London as follows:--Pp. 1-21 in Contrib. VIII, Trans. Zool. Soc., Vol. V, 1865 (1866), pp. 243-260; pp. 21-30 in Contrib. IV, op. cit. iv, 1853 (1862), pp. 77-86; and pp. 30-52 in Contrib. VIII, op. cit. V, 1865 (1866), pp. 260-281. The monograph represents a high point in Owen's long series of studies on the primates. It includes Owen’s “most elaborate defence” of the position he had taken in the infamous “hippocampus debate” with Thomas Huxley, in which Huxley publicly challenged Owen’s claim that man’s brain differed qualitatively from those of all other primates (and indeed, all other mammals). Rupke, Richard Owen: Victorian Naturalist, pp. 290-291.

Digital facsimile from the Internet Archive at this link.