INTRODUCTION TO SOCIOLOGY 621
ism this variable equilibration is the result of an internal elabora- tion, which continually modifies both the materials borrowed from the environment and the structure, as well as the functioning resulting from the superior combinations produced by this assimi- lation and this elaboration. Every organism is not only limited in its structure at any period whatever of its growth, but even this evolution is limited :
First, by their very perfection, the organisms come to be no longer s is- ceptible to change in the presence of new conditions ; for example, the horse, having now only a toe. His species would perish, if he were able to subsist only by a new modification of the feet.
Secondly, at every epoch, there has been on the surface of the globe a category of predominant organisms, very perfect and not without descendants. Nevertheless the aristocracy of the subsequent epoch never springs from the preceding aristocracy, but always from unfinished types, from characters which are still simple, and which have retained a structure susceptible of varied adaptations. 1
Later, while studying the social types, we shall see that the essential variations of these types are likewise limited in such a manner that it is always possible to reduce them to a few charac- teristic types. We shall show that this conclusion, which pre- sents important analogies with the theory of limited variability set forth by Geoffroy Saint-Hilaire in his Histoire naturelle ge'ne'rale des regnes organiques, must be based upon the fact that, the social material being limited, the many combinations which may arise, although incalculable in the present state of our knowledge, are also necessarily limited. This is a new explanation of the law of the apparent return to the primitive forms, which must be limited, as in zoology, by this other law that evolution is not reversible, although this latter law may be far from being so rigorous in sociology as in zoology. Finally, our theory of the limits of social variation is totally different from the theory of form- limits of A. Loria and other sociologists.
The primary form resulting from this continual equilibration of organized matter is the consequence of this rudimentary gen- eral necessity. It manifests itself by the appearance at the sur-
1 A. LAMEERE, Le transformisme.
