3«Section I.V. G. Ruggeri.
di Mus musculus, quella dalla quale sono derívate le altre varietá. Allora
con molta probabilitá, anche per l’Uomo i caratteri dominanti sono pure gli
originari, e il bruno (da non confondere col Negro) a capelli lanosi appare
come un tipo ancestrale, nei limiti delle esperienze fatte.
THE SO-CALLED LAWS OF INHERITANCE IN MAN.
By Professor V. Giuffrida-Ruggeri,
University of Naples.
Morselli, in his great work, “ General Anthropology,” recently
completed, several times touches upon the possibility that the Mendelian
laws find verification in man. Thanks to recent researches, carried out
chiefly in the United States and England, it is now certain that the races
of man act exactly as the races of animals. In order fully to understand
such researches it is, however, opportune to allude to the classical experi
ments of Cuenot upon mice, to which I may briefly refer.
Every race, whether a sub-species or a variety—zoologists employ these
three words without much verbal subtlety—has an hereditary possession of
certain characters, a possession which is completely transmitted to the
descendants, in whom is preserved the same germ-plasm as in the progenitors,
who have the same biotype (Johannsen). Cuenot has investigated the
behaviour of the germ-plasm of the grey mouse, which may be considered
as the common ancestor of other forms or races or varieties of Mus musculus.
This contains a certain number of determinants (not in Weismann’s sense)
or hereditary unities or genera, each of which is capable of changes or
mutations. In the ancestral type there are at least six sorts or categories
of determinants, which may be conventionally designated by the letters
C, G, F, M, U, R. If any one of these determinants is modified we obtain
another elementary form of mouse or genotype, which differs in some respects
from the ancestor, which is a mutation (not in the sense of De Vries)
slight or marked of it. The various categories of determinants have
presented, in the course of time, a variable number of determinants, one,
two, or more. Nine mutations of the original determinants of the grey
mouse are thoroughly ascertained, then in all fifteen determinants of as
many characters. Of these characters some are dominant, others are subject,
recessive or latent. In the general compendium, which we reproduce here,
the dominants occupy the first row, and so the others in succession in order
of dominance, the capital letters indicate the determinants of the grey
mouse, which are all, except one, in the first row, that is to say, are dominants.
