Chap. I. HOMOLOGICAL STRUCTURE. 11 



in the brain of man has its analogy in that of the orang ; 

 but he acids that at no period of development do their 

 brains perfectly agree ; nor could this be expected, for 

 otherwise their mental powers would have been the same. 

 Vulpian 2 remarks : " Les differences reelles qui existent 

 " entre l'encephale de l'homme et celui des singes supe- 

 " rieurs, sont bien minimes. II ne faut pas se faire 

 " d'illusions a cet egard. L'homme est bien plus ~pves 

 " des singes anthropomorphes par les caracteres anato- 

 (S miques de son cerveau que ceux-ci ne le sont non- 

 " seulement des autres mammiferes, mais memes de 

 " certains quadrumanes, des guenons et des macaques." 

 But it would be superfluous here to give further details 

 on the correspondence between man and the higher 

 mammals in the structure of the brain and all other 

 parts of the body. 



It may, however, be worth while to specify a few 

 points, not directly or obviously connected with struc- 

 ture, by which this correspondence or relationship is 

 well shewn. 



Man is liable to receive from the lower animals, and 

 to communicate to them, certain diseases as hydro- 

 phobia, variola, the glanders, &c. ; and this fact proves 

 the close similarity of their tissues and blood, both in 

 minute structure and composition, far more plainly than 

 does their comparison under the best microscope, or by 

 the aid of the best chemical analysis. Monkeys are 

 liable to many of the same non-contagious diseases as we 

 are ; thus Rengger, 3 who carefully observed for a long 

 time the Cebus Azarss in its native land, found it liable 

 to catarrh, with the usual symptoms, and which when 



2 'Lee. sur la Phys.' 1866, p. 890, as quoted by M. Dally, 'L'Ordre 

 des Primates et le Transformisme,' 1868, p. 29. 



3 ' Naturgeschickte der S'augethiere von Paraguay,' 1S30, s. 50. 



