458 Prof. Owen on the Cerebral Characters of Man and the Ape. 



A transverse eminence, called pes accessorius or eminentia col- 

 lateralis (by the Dutch anatomists termed 'pes hippocampi 

 minoris '), is " placed between the hippocampus major and minor 

 at the junction of the posterior with the descending cornu^' 

 (p. 465). This latter part is indicated " als aanduiding van den 

 kleinen vogelklaaw [pes hippocampi minor) (pi. 2. fig. 4 e)," p. 9 *. 

 There is no continuation of the lateral ventricle curving back- 

 wards, outwards, and inwards, nor any eminence accompanying 

 it in those directions and extent, in any known Ape. 



However, I have no more doubt that my fallible fellow- 

 labourers in anatomical science have spoken the truth, as they 

 conceived it, in affirming the higher Apes to possess the ' poste- 

 rior lobes,' ' posterior horn of the lateral ventricle,' and ' hip- 

 pocampus minor,' than that I believe myself to be enunciating 

 a strictly scientific truth when, agreeably with the definitions of 

 those parts, I affirm them to be peculiar to the human species. 

 I am. Gentlemen,* 



Your obedient Servant, 



Richard Owen. 



EXPLANATION OF THE PLATES. 



Plate XIX. 



Fig. \. Upper surface of the brain of a Negro, nat. size. (Phil. Trans. 



1836, pi. 32, Tiedemann.) 

 Fig. 2. Upper surface of the brain of a Chimpanzee, nat. size (Nieuwe 

 Verhandlingen iler erste Klasse van het Koningl. Nederlandsche 

 Instituut, plaat 1. fig. 2 ; Schroeder van der Kolk and W. Vrolik) : 

 c, cerebrum ; b, cerebellum. 



Plate XX. 



Fig. 1. Left moiety of a bisected brain of a Negro, nat. size. (Phil. Trans. 

 1836, pi." 33, Tiedemann.) 



Fig. 2. Left moiety of a bisected brain of a Chimpanzee, nat. size. (Nieuwe 

 Verhandlingen, &c., plaat 2, fig. 1 ; Schroeder van der Kolk and 

 W. Vrolik.) 



Fig. 3. Right moiety of a dissected brain of a Chimpanzee, showing the 

 lateral ventricle, nat. size. [lb. pi. 2. fig. 4 ; ib.) 

 In this and the following figure — a, corpus striatum ; p b, taenia 

 hippocampi; c, hippocampus major; d, descending cornu of ven- 

 tricle ; e, pes accessorius, seu pes hippocampi minoris ; f. hip- 

 pocampus minor ; g, posterior horn of lateral ventricle. 



Plate XXI. 

 Right moiety of a dissected Human brain, showing the lateral ven- 

 tricle, nat. size. (Gray, Anatomy, Descriptive, &c., 8vo, p. 462. 

 fig. 244.) 



* Ontleedkundige, &c., he. cit. 



