The sexual question

by Auguste Forel

(1). In its principal characters, each individual is the copy of its parents or direct ancestors, with correlative sexual peculiarities which we have mentioned, and with individual variations due to the combinations of varieties by conjugation, and the alternating or unequal ecphorias of hereditary characters; that is to say paternal or maternal hereditary engrams.

(2). No individual is absolutely identical with another.

(3). On the average, each individual resembles more especially its direct ancestry and its parents, and differs more markedly from its parentage the more this is remote.

We shall see later on that the ancestral relationship of the different groups, species and varieties of animals has been fairly well fixed, and we may say that the third of the laws stated above is equally true in a wider sense. In fact the species and varieties of animals which are near related resemble each other, while the genera, families and classes are more dissimilar as their relationship is more remote. We employ here the terms resemblance, homology and difference in their profound and general sense. Certain purely external resemblances, due to phenomena of convergence, must not be considered as homologies in the sense of hereditary relationship. Thus, in the language of natural history we do not say that a bat resembles a bird, nor that a whale resembles a fish, for here the resemblances are due simply to aërial or aquatic life which produces the effects of convergence, while the internal structure shows them to be quite dissimilar organisms. Although it swims in the sea the whale is a mammal; its fins at first sight resemble those of a fish, but they are really the homologues of the four limbs of other mammals and contain the corresponding bones.

In man, we see that brothers and sisters resemble each other in a general way, but that each one is dissimilar in some respects from the others. If we compare different families with many children we find that brothers and sisters resemble each other the more their parents are alike and come from a uniform ancestry which has undergone little crossing, while the crossing of different races and human varieties results in the production of individuals which differ from each other considerably, even when they come from the same couple.

If we examine things more closely, we find that the characters of each of the offspring of the same couple present neither simple repetition nor an equal mixture of the peculiarities of the parents, but very diverse combinations of the characters of several ancestors. For instance, children may bear a striking resemblance to a paternal grandfather, a maternal grand-aunt, or a maternal great-grandmother, etc. This is called atavism. Some children resemble their father, others their mother, and others a kind of mixture of father and mother.

A closer examination reveals further very curious facts. An infant which, in its early years, strongly resembles its father, may later on resemble its mother, or inversely. Certain peculiarities of a certain ancestor appear suddenly, often at an advanced age. It is needless to say that peculiarities concerning the beard cannot appear till this has grown, and this simple fact is so characteristic that it has been called hereditary disposition. Everything may be transmitted by heredity, even to the finest shades of sentiment, intelligence and will, even to the most insignificant details of the nails, the form of the bones, etc. But the combinations of ancestral qualities vary so infinitely that it is extremely difficult to recognize them. Hereditary dispositions arise from the energy of two conjugated germs during the whole of life and till death. Old people sometimes develop peculiarities hitherto unknown in them, owing to the fact that one or more of their ancestors also presented the same phenomena at an advanced age.

Semon has clearly proved that, although forming an infinite number of combinations the engrams or hereditary energies never blend in the proper sense of the term, and in the light of his exposition the above facts are more clearly explained than they had been hitherto. The experiments of Mendel have shown in plants a certain alteration in the hereditary ecphorias of the products of dissimilar parents.

Certain parental characters, according as they are added or subtracted, may disappear during one or two generations, to reappear all the more strongly in the following generations. In short, there are a number of phenomena, the laws of which may be more clearly explained to us in the future.

To sum up, each individual inherits on the average as much from his paternal as from his maternal side, although the minute nucleus of the spermatozoid is the only agent concerned on the paternal side, while the mother provides not only the egg which is much larger, but also nutrition during the nine months of embryonic life. We can only conclude that in the egg also it is only from the part of the nucleus which conjugates with the male nucleus that arise all the inherited maternal peculiarities; that all the rest is only utilized as food; and that the nutritive blood of the mother in no way influences the inherited energies of the offspring.