Chap. I. 
HOMOLOGICAL STRUCTURE. 
11 
in the brain of man has its analogy in that of the orang ; 
but he adds 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. 
Yulpian 2 remarks : “ Les differences reelles qui existent 
“ entre 1’encephale de l’homme et celui des singes supe- 
cc rieurs, sont bien minimes. II ne faut pas se faire 
“ d’illusions a cet egard. L’homme est bien plus pres 
“ des singes anthropomorphes par les caracteres anato- 
“ miques de son cerveau que ceux-ci ne le sont non- 
“ seulement des autres mammiferes, mais rnerues 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 Azarx in its native land, found it liable 
to catarrh, with the usual symptoms, and which when 
2 4 Le$. sur la Phys.’ 1866, p. 890, as quoted by M. Dally, * L’Ordre 
des Primates et le Transformisme/ 1868, p. 29. 
3 4 Naturgesehichte der Saugethiere von Paraguay,’ 1830, s. 50. 
