ly disposed to regard races rather
as originally different species than as mere varieties. The permanence
of certain types in the midst of the most hostile influences,
especially of climate, appeared to favor such a view, notwithstanding
the shortness of the interval of time from which the historical
evidence was derived. In my opinion, however, more powerful reasons
can be advanced in support of the theory of the unity of the human
race, as, for instance, in the many intermediate gradations in the
color of the skin and in the form of the skull, which have been made
known to us in recent times by the rapid progress of geographical
knowledge--the analogies presented by the varieties in the species of
many wild and domesticated animals--and the more correct observations
collected regarding the limits of fecundity in hybrids. The greater
number of the contrasts which were formerly supposed to exist have
disappeared before the laborious researches of Tiedemann on the brain
of negroes and of Europeans, and the anatomical investigations of
Vrolik and Weber on the form of the pelvis.

On comparing the dark-colored African nations, on whose physical
history the admirable work of Prichard has thrown so much light, with
the races inhabiting the islands of the South Indian and West
Australian archipelago, and with the Papuas and Alfourous (Haroforas,
Endamenes), we see that a black skin, woolly hair, and a negro-like
cast of countenance are not necessarily connected together. So long as
only a small portion of the earth was known to the Western nations,
partial views necessarily predominated, and tropical heat and a black
skin consequently appeared inseparable. "The Ethiopians," said the
ancient tragic poet Theodectes of Phaselis, "are colored by the near
sun god in his course with a sooty luster, and their hair is dried and
crisped with the heat of his rays." The campaigns of Alexander, which
gave rise to so many new ideas regarding physical geography, likewise
first excited a discussion on the problematical influence of climate
on races. "Families of animals and plants," writes one of the greatest
anatomists of the day, Johannes Muller, in his noble and comprehensive
work, "Physiologie des Menschen," "undergo, within certain limitations
peculiar to the different races and species, various modifications in
their distribution over the surface of the earth, propagating these
variations as organic types of species.

"The present r