es as the direct ancestor of man, by others as
a side-track failure in the attempt at the evolution of man. The problem
of the monophyletic or polyphyletic origin of the human race has also
been much discussed. Sergi (Sergi G. "Europa", 1908.) inclines towards
the assumption of a polyphyletic origin of the three main races of man,
the African primitive form of which has given rise also to the
gorilla and chimpanzee, the Asiatic to the Orang, the Gibbon, and
Pithecanthropus. Kollmann regards existing human races as derived from
small primitive races (pigmies), and considers that Homo primigenius
must have arisen in a secondary and degenerative manner.

But this is not the place, nor have I the space to criticise the various
special theories of descent. One, however, must receive particular
notice. According to Ameghino, the South American monkeys (Pitheculites)
from the oldest Tertiary of the Pampas are the forms from which have
arisen the existing American monkeys on the one hand, and on the other,
the extinct South American Homunculidae, which are also small forms.
From these last, anthropoid apes and man have, he believes, been
evolved. Among the progenitors of man, Ameghino reckons the form
discovered by him (Tetraprothomo), from which a South American primitive
man, Homo pampaeus, might be directly evolved, while on the other hand
all the lower Old World monkeys may have arisen from older fossil
South American forms (Clenialitidae), the distribution of which may
be explained by the bridge formerly existing between South America and
Africa, as may be the derivation of all existing human races from Homo
pampaeus. (See Ameghino's latest paper, "Notas preliminares sobre el
Tetraprothomo argentinus", etc. "Anales del Museo nacional de Buenos
Aires", XVI. pages 107-242, 1907.) The fossil forms discovered by
Ameghino deserve the most minute investigation, as does also the fossil
man from South America of which Lehmann-Nitsche ("Nouvelles recherches
sur la formation pampeenne et l'homme fossile de la Republique
Argentine". "Rivista del Museo de la Plata", T. XIV. pages 193-488.) has
made a thorough study.

It is obvious that, notwithstanding the necessity for fitting man's line
of descent into the genealogical tree of the Primates, especially the
apes, opinions in regard to it differ greatly in detail. This could not
be otherwise, since the different Primate forms, especially the fossil
forms, are still far from being exha