THE ORIGIN OF MAN. 265 
heredity, but I have always insisted and do now insist that, with 
man, all heredity is partial. A general heredity in the zodlogical 
sense, where all characteristics are preserved from generation to 
generation, is not to be found among men. If botanists have 
begun on the basis of local variations to make subordinate divisions, 
to fix individual sub-species within the same species, variations 
with inherited characteristics, nothing is easier than out of these 
sub-species to make new species. But this circumstance, that 
within the same species many individual variations occur, and that 
within the same species some peculiarities are transmitted as 
inherited, only proves that the same individual may inherit various 
heredities. Thus it is known that one may inherit peculiarities 
from father and from mother, and so unite in himself a double 
heredity; he may show peculiarities that correspond to the 
characteristics of his grandfather or grandmother, whilst he shows 
other characteristics that belonged to his parents. In the same 
individual there wis united a sum of partial inheritances, which are 
limited to smaller or greater parts. There may be many such 
portions, but that all portions agree cannot be proved. Only with 
twins does it sometimes occur that, except by the most careful 
observation, they cannot be distinguished. When they are dis- 
tinguished, it must be by specialmarks.” (After referring to one 
or two examples of heredity, Professor Virchow continued) :— 
“We do not know certainly how far the sphere of heredity 
reaches. By reason of this uncertainty the matter of human 
relations is very largely complicated. ‘That, for instance, human 
development may be influenced by climate and other cireumstances 
of life, is probable, although at present no cogent reasons prove 
that existing men were able to change themselves wholly. We 
know of no fact that proves with certainty that the local climate 
could change any men to that form of man native there. 
“Thus far have we retreated in our knowledge. You will say, 
That is strange ! in the last twenty years you have gone back, you 
know less than the people of twenty years ago! I agree that, in 
fact, we know less, but it is our pride that we have so far clarified 
our knowledge that we kNow what we really know. ‘T'wenty years 
ago men did not know so much; they only ‘ believed they knew.’ 
We have now made this pretended knowledge the subject of 
scientific test. Natural Science has taken possession of its domain, 
