136 “The Descent of Man” 
But this is not the place, nor have I the space to criticise the 
various special theories of descent. One, however, must receive par- 
ticular 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'. 
The fossil forms discovered by Ameghino deserve the most minute 
investigation, as does also the fossil man from South America of 
which Lehmann-Nitsche? 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 exhaustively known. But one 
thing remains certain,—the idea of the close relationship between 
man and monkeys set forth in Darwin’s Descent of Man. Only 
those who deny the many points of agreement, the sole basis of 
classification, and thus of a natural genealogical tree, can look upon 
the position of Darwin and Haeckel as antiquated, or as standing 
on an insufficient foundation. For such a genealogical tree is nothing 
more than a summarised representation of what is known in regard 
to the degree of resemblance between the different forms. 
Darwin’s work in regard to the descent of man has not been 
surpassed; the more we immerse ourselves in the study of the 
structural relationships between apes and man, the more is our path 
illumined by the clear light radiating from him, and through his 
calm and deliberate investigation, based on a mass of material in 
the accumulation of which he has never had an equal. Darwin’s 
fame will be bound up for all time with the unprejudiced investiga- 
tion of the question of all questions, the descent of the human race. 
1 See Ameghino’s latest paper, ‘‘Notas preliminares sobre el Tetraprothomo argentinus,” 
etc. Anales del Museo nacional de Buenos Aires, xvi. pp. 107—242, 1907. 
? «Nouvelles recherches sur la formation pampéenne et l’homme fossile de la République 
Argentine.” Rivista del Museo de la Plata, T. x1v. pp. 193—488. 
