Among physical qualities I have made note of the fact that from alcoholic or aged parents were descended children in whom degenerative physical characteristics were most frequently apparent, recalling some features of an inferior human type, such as exaggeration of the frontal sinuses, the torus occipitalis, ears with the Darwinian tubercles prominent, the forehead receding, etc. At the same time the ascendants of those who presented typical and anomalous characters, due to morbid influences of various kinds and following on faulty development of the fœtus, such as cretinism, congenital goître, nasal deflections, strabismus, plagio-cephaly, hydrocephaly, dental malformation, etc., showed a large number of alcoholics and epileptics.
The explanation of the pernicious consequences to the psycho-physical characters of the children of parents too young or too advanced in age does not present much difficulty.
At the younger period the organism is still in process of formation; the incomplete development of the skeleton, as of all the other organs, continually absorbs a mass of plastic materials necessary to the formation of offspring. So we may consider that the faults of children born of too young parents are due to an incomplete development because of the insufficiency of plastic material.
We must, on the other hand, seek in the conditions which accompany old age for the reason why it has a disastrous influence on the vitality of the germinal elements of the parents and predisposes the descendants to various forms of physical and moral degeneracy.
During this period we have in the tissues, instead of a development and renewal of protoplasm, the tendency to an accumulation of fat; and in the whole organism, chiefly in the tissues of the arterial system, we find the tendency to a deposit in their structure of an amorphous substance which converts the supple elastic canals into rigid tubes; and from this a general slowing up of the organic functions (circulation, oxidation, secretion) results; the blood, not reaching the degree of elaboration which it possessed before, acquires a greater acidity, and cannot by the ordinary excretory channels so quickly get rid of the catabolic products with which it is charged.
By reason of these conditions the organism of older people undergoes a sort of slow and gradual intoxication, which, at the same time as it shows itself in the individual by the gradual languishing of all his functions, influences in a disastrous manner the germs which develop within him, and predisposes them to become beings condemned to degeneracy.
Consequently this cause of degeneracy enters the general category of intoxications.