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modern Mati so high above the animals, has not been realiz,ed. 

 Tiiis however does not apply to Pithecanlhropiis, if this fossil 

 ajjthropomorphoiis Primate is not considered to be of a separate 

 family, but leckoiied to belong to Ihe Hominides. For he possessed 

 only two thirds of tiie cerebral volume of the Australian aboriginal 

 (which he resembled in body size and also in the main features of 

 his skeleton), but tivice that of anthropoid apes of the same body 

 size. But also this "precursor of Man" is of a late date — probably 

 not before the Fbocene. The transition from such a volume of brain 

 as that of the Anthropoid Apes to the modern human volume seems 

 at all events to have been a rapid one, and halfway there is still 

 that of Pithecanthropus. 



This organ, upon which depend inscrutable attributes of animal 

 life, of the greatest degree, shows therefore an indubitable progress 

 in the geological past. But it is also certain that this phylogenetic 

 growth of the encephalon, as a whole and in its most compounded 

 parts, took place with starts, and much seldomer than that of the 

 other parts of the body, of which now one part, now another is 

 again and again seen, in the most diversified ways, to increase in 

 volume and complexity, the whole body not seldom growing into 

 gigantic dimensions. 



The question now suggests itself what the proportion has become 

 between the volume of the brain and the size of the body through 

 phylogenetic and ontogenetic growth, i. e. increase from species to 

 species and from individual to individual, in adult animals of the 

 present time. 



It can easily be ascertained that the brain volume, reached by a 

 species of animals in adult state, depends both on the size of the 

 body and on the stage of development attained by the brain, which 

 determines the degree of the functions of the organ. 



It is not astonishing that the absolute brain weight of Man is 

 surpassed by that of the Elephant and Ihe large whale species. 

 The largest whale species, which is a thousand times heavier than 

 Man, possesses five times his brain weight. It is also self-evident 

 that such a gigantic species of the cat family as the Tiger has much 

 larger brain than the Domestic Cat; to sixty-four times the body 

 weight of the latter, the Tiger has ten times its brain weight. Keeping 

 to the same species we find in an adult dog of the size of the 

 Wolf, of about 40 kg. body weight, double the brain weight 

 of a lap-dog weighing about 2 kg. 



But besides on the size of the body, the brain volume depends 

 also on the stage of development of this organ, on the particular 



