Page:American Journal of Sociology Volume 9.djvu/407

 INTRODUCTION TO SOCIOLOGY 393

The general variability of organisms has no further need of being demonstrated. It is the constant result of certain relations between their internal structure and their external environment. For illustration, the ordinary horses imported into the Falkland Islands produce from the first generation smaller offspring, and after a few generations the species degenerates altogether. This alteration of structure is in connection with the bad food and humid climate of the country.

In primitive or other human societies whose climatic and alimentary environment is favorable, there will be brought about in the genesial relations some advantageous variations, in the sense, for example, of an extension and consolidation of the family life. Notably more value will be attached to the preser- vation of children than in a society where this preservation con- stitutes a disadvantageous burden. Children will be the object of more care and of more extended education. Also more care will be given to the women and to the old men.

What is it necessary to understand by "heredity" in the case of horses and men ? Is it necessary to comprehend, as is gener- ally supposed, that the characteristics acquired by the individual under the influence of the environment are fixed and transmitted hereditarily in thespecies ? According toWeismann.the acquired characteristics are not transmitted ; at least, nothing so far proves such transmission. There are merely some advantageous and disadvantageous modifications in the several aptitudes of the germinal plasm of each organism. For instance, in the case of the horse of the Falkland Islands, in an unfavorable climate and with deficient alimentary conditions, the horse suffers not only in its structure, but also in its germinal cells. There is a diminution in the size of the cell, to which must be added insufficent nour- ishment during growth ; but there is no transmission, through the germinal cells of certain peculiarities which are manifested first among adult animals under the influence of the climate. The degeneracy of the species under these conditions is due entirely to natural selection, which operates in the sense of the preserva- tion of the smallest horses, that is, of those whose germ has been enfeebled. This explanation is conformable to the conclusions