i8Section I.G. Sergi. 
which so much importance is justly attached in the study of man. The con­ 
ception of such an evolution has come to anthropologists from the fact of 
there having been observed in some regions a substitution of the brachi- 
morphic type for the dolicomorphic, and Europe has been the field of the 
change, which has given rise to this idea. Not knowing or not wishing to 
seek elsewhere the origin of the brachimorphic forms, and not being willing 
to regard them as immigrant, they have considered them as originating by 
an evolution from the other type. 
But the theory, and with it the cause of the supposed evolution are 
wanting—these they seek by speculating. Is the plain or the mountain the 
cause of this phenomenon? But this view does not find support in fact, 
because the brachimorphic occupies all the great plain of Russia and at 
the same time the heights of the Alps, and similarly elsewhere, i.e., 
occupies plains and mountains indifferently. But, perhaps, it is a severe 
or a mild climate which is the cause? But the facts do not confirm this 
theory either. The Esquimaux, the most jAjctic people, are completely 
dolico, while the Samoiedes at the northern corner of Asia, the Laplanders 
at the northern extremity of Europe are brachimorphic, like the Italians of 
the Po regions and many of the Balkan peoples. Is it the habits and the 
customs of peoples which act upon the muscles of the head and so transform 
the cranial structure? This is the opinion of Nystrom, but in that case 
analogous or identical effects should be found amongst peoples with the 
same customs, and nothing of that sort happens. Then, is it the surrounding 
circumstances, or as some say the environment, which transforms the skull? 
Boas believes that he has demonstrated the phenomenon among the immi­ 
grants in the United States of America. 
Against this supposed change which seems demonstrated by Boas by 
statistics, I have been able to establish that it is a pure effect of illusions due 
to the statistical method employed by the author. Boas regards as demon­ 
strative the averages obtained from the measurements—cranial, facial, and 
other—without taking account of the elements from which the averages are 
derived, which are heterogeneous. It can easily be demonstrated that such 
irrational averages amongst the descendants of the immigrants in the United 
States of America are not inconsistent with those of the same European 
populations from which the emigrants are derived; and, besides, it can be 
shown that the composition of the series from which the averages are obtained 
is not substantially different in the children of the emigrants and in the 
European populations from whom the emigrants come. It would be strange 
if changes occurred in opposite directions as Boas asserts; for instance, if 
brachicephalic Hebrews became dolicocephalic, and dolicocephalic Sicilians 
became brachicephalic, and this in a region where, since prehistoric times, 
the dolico and the brachicephalic forms have co-existed. 
Other anthropologists believe that they can trace the evolution of the 
cranial form from dolico into brachimorphic, and explain it by the effect of