TRANSACTIONS OF SECTION D. 419 
clear evidence of a considerable change in climatic conditions since the period 
when Glossopteris flourished on the Antarctic continent, there is no adequate 
reason to assume any change in the position of the earth’s axis. Meagre as it 
is, the material collected by the Polar party calls up a picture of an Antarctic 
land on which it is reasonable to believe were evolved the elements of a new 
flora that spread in diverging lines over a Paleozoic continent, the disjuncta 
membra of which have long been added to other land-masses, where are preserved 
both the relics of the southern flora and of that which had its birth in the north. 
The President (Prof. W. Barrson) then declared the discussion closed. 
4. Heredity of some Emolional Traits. 
- By Professor C. B. Davenport. 
While sociologists, who lay great stress on the importance of conditions in 
determining human traits, have been forced to admit the hereditary basis of 
feeble-mindedness, they still hold, for the most part, to the view that in the 
moral field heredity plays little part. Both to test this view and _ because 
of the theoretical importance of the subject, the topic of inheritance of the 
traits of persons of the criminalistic type was undertaken. 
The base of the study is the family history of 165 wayward girls in State 
institutions of the United States. The family histories were secured by 
specially trained ‘ field-workers,’ operating in conjunction with State Institu- 
tions and the Kugenics Record Office. In addition, for the study of special 
topics a mass of other family histories, some 2,500 in number, was drawn upon 
freely. 
As a general result of these studies about twenty traits were considered in 
some detail. Many did not yield any clear-cut results; but in at least five 
cases the hereditary factor was clear and evidently determined the behaviour. 
1. The tendency to tantrums—or violent outbursts of temper—in adults is 
inherited as a dominant trait; that is, it does not skip generations. In several 
scores of histories it was possible to trace the tendency back three, four, and 
eyen five generations. 
2. Violent eroticism, or striking lack of self-control in the sex sphere, is 
also a positive character, and likewise is traced back without breaking genera- 
tions; and half of the offspring of a highly erotic person show similar irresistible 
impulses. 
3. Impulsions to suicide are accompanied by depressions. In harmony with 
what has been shown for some types of mania-depression insanity, it appears 
that this depression is inherited as a recessive or negative character. It 
ordinarily skips generations; but the tendency is ordinarily found on both sides 
of the parentage of the affected individual. 
4, 5. Two other traits appear, remarkably enough, as sex-linked characters. 
They are transmitted through mothers to some or all of their sons. They 
appear in daughters, typically, only when shown by the father, and the tendency 
is carried also by the mother. If both parents show the trait all children have 
the tendency to develop, in due time, the trait. These traits are dipsomania 
and certain other types of irresistible impulsions to drink, and nomadism, or 
the impulsion to wander. 
5. The Hormone Theory of the Heredity of Somatic Modifications. 
By Dr. J. T. Cunnincuam, M.A. 
Darwin’s theory of the origin of species was founded on the assumption that 
species were divided by differences of adaptation. It may be true that allied 
species sometimes differ slightly in their mode of life, and show differences 
of structure corresponding to these differences of action; but investigation has 
entirely failed to prove any utility or bionomical significance for many specific 
and other diagnostic characters, and the assumption that such characters are 
due to correlation with adaptive characters is without foundation. 
Mendelism in itself throws no direct light on the origin of characters; it 
_deals merely with their transmission. It is inferred, however, by the 
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