3Q6 THE AMERICAN JOURNAL OF SOCIOLOGY
mits it to react upon the external influences in a manner different from that of any other structure, which is the reason that it cannot modify itself, no matter what its form, and which demands that there be quite numerous pos- sibilities of very definite variations. It also renders possible that certain peculiarities in the constitution of a species may disappear and be replaced by others. We cannot discover varieties of vertebrates without the vertebral column or fixed axis, not because the vertebral column is indispensable as a support for the body, but rather because this form has been transmitting itself from time immemorial, and on that account has become so fixed that it is no longer able to be produced with sufficient variations to menace its existence. The idea of the origin of the hereditary variability through the amphigonic reproduction clearly explains how the oscillations of an organism may be in a certain measure purely superficial, and so explains the impassi- bility of the fundamental bases which have been so long acquired. 1
These biological considerations are relatively common to the structure of societies. They confirm our sociological theories, to which we shall have to return in due time, relating to the greater fixity and stability of forms, and the most general social functions, and especially of the most anciently constituted forms in each function. They are likewise the primary explanation of the phenomena and laws of correlation and harmony, which at each moment and in each civilization are revealed to us through the social organizations considered in their ensemble, and they also serve as an interpretation of the frequent incoherences of social organization.
That which Weismann calls "the impassibility of the funda- mental bases" explains how the biological organisms are natu- rally limited in their form and growth. But even in biology it would not be necessary to attach an absolute character to this impassibility. For the strongest reasons it is necessary to avoid this in sociology, where even the most fundamental forms are only relatively more fixed than those which are more superficial and more recently acquired. Some sociologists, as A. Loria, have deduced too rigorously from a sociological principle, itself viewed in a too inflexible manner, that societies also are not able to exceed certain limited forms. The profound and learned Italian sociologist especially applies this principle to the eco-
1 A. WEISMANN, La signification de la reproduction sexuelle pour la thtorie de la .selection naturelle.
