667 
of the nervous system) and in the relative development of the parts 
of the brain of higher and lower function between different animal 
species, apparently in accordance with their psychical capacities. 
With equal body weight as the Chimpanzee, Man has indeed three 
and a half times the brain weight of this most human-like animal 
species; the Chimpanzee, in its turn, has twice as much brain as 
would possess a Macaque, obtaining the same body weight, ten times 
as much brain as a Mouse or a Rat of the same body weight. 
Besides, the different Mammals differ very considerably with regard 
to the proportion of the more highly to the lower organized parts 
of the brain. It is beyond our power to estimate the amount of the 
psychical differences between the animal species, but these psychical 
differences are connected, so far as we can see, with the well- 
calculated relative brain quantity and the relative development of 
more highly organized parts of the brain. 
Though, in view of those facts, we cannot reasonably assume the 
existence of essential, qualitative differences between the species, either 
in one or in the other respect, yet there is some difficulty in 
conceiving that even in case of the greatest quantitative differences, 
essentially equal ‘‘psychical powers’, only differing in degree, cor- 
respond to this qualitative similarity of the nervous system. They 
think that a certain quantity of the brain, though it cannot be 
anatomically separated from the rest, would be mechanically inde- 
pendent of the body, and specially set apart for the intellect. 
This view formulated in 1885 by Manoovrier’), though with a 
great deal of reservation and for want of something better, was 
refuted by Lapricgue?) in 1907. The latter demonstrated that an 
equal brain quantity 2 can, indeed, be calculated every time for 
two psychically equivalent species, but not for three or more. 
Between the Lion and the Puma the calculation of the “brain 
quantity for the psychical functions” gives a value four times greater 
than between the Puma and the Cat. Yet these members of the 
Cat-tribe may be assumed to’ have quite the same organization of 
the brain. 
Ll can now add a few more trios of other genera to these three 
species of my paper of 1897. 
In the Dog-tribe, the value of 7 found between the Wolf and the 
1) L. Manouveien, Sur l'interprétation de la quantité dans l'encéphale. Mémoires 
de la Société d'Anthropologie de Paris. 1885. 2e Série, Tome 3me, p. 316 et seq. 
5 L. Laricgue in Bulletins et Mémoires de la Société d'Anthropologie de Paris 
1908, (Séance du 2 Mai 1907), p. 256 et seq. 
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