THE LIFE OF MAMMALS 
Pliocene epoch next preceding the Glacial epoch. Only the 
top of the skull, a thigh bone, and two teeth are known, 
Pithecan- and they indicate an erectly walking animal, about 
farepus. five feet and six inches tall, which in general appear- 
ance, and in having a brain capacity almost equal to that of the 
earliest known human beings (the cave dwellers of the Nean- 
derthal in France), was much nearer man than is any modern 
ape. This creature is truly, as Professor Haeckel puts it, 
“the long-searched-for missing link,” in other words, represents 
the commencement of humanity.* It is named Pithecanthropus 
erectus. 
The rude, chipped-stone implements found in the red clay on 
the chalk downs of southern England,” and in similar Pliocene 
deposits in neighboring parts of France and Belgium, denote 
the existence of, in that region, ‘“‘ Eolithic man,” a being capable 
at least of making these objects contemporary with Pithecan- 
thropus in Java; but no fossil bones of Preglacial man in 
Europe have been recovered. 
Chimpanzees, Gorillas, Orang-utan, and Gibbons 
The chimpanzees, gorillas, orang-utan, and gibbons or 
“anthropoid apes,” differ from mankind principally in the form 
of the skull, and in the great length of the arm as compared with 
the leg. The foot is more handlike, too, a tree-gripping rather 
than a ground-stepping organ. Nevertheless, all can stand or 
even walk fairly erect upon the ground, balancing themselves 
by outstretched arms; when they are in haste, however, and, 
indeed, ordinarily, they rest their weizht upon their long arms 
and closed hands, the knuckles touching the ground, and so 
progress on all fours or swing along somewhat like a man on 
crutches. The spine of the chimpanzee alone among them 
shows much approach to an S-like curve, and the skull, which 
is longest fore and aft, is set on the neck well forward of its 
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