236 THE AMERICAN JOURNAL OF SOCIOLOGY
remarkable stability, which extends partly to the social world, belongs evidently to the strict static connection which binds together the physical, botanical, zoological, and sociological phenomena. This interpretation is the natural and positive explanation of the origin of species.
The formation of species is the outcome of the general phe- nomena of the variability of organized beings. This variability is dependent upon the influence of the environment and accesso- rily upon modifications accidentally introduced in their structure. Heredity fixes the variations and transmits them to the descend- ants. Every cell in dividing distributes among the daughter- cells some essential characteristics of the mother-cell, including those characterics which are the result of variation. Then ensues the struggle for existence, which proceeds by the elimination of the less fit, in the relative sense of the word. This struggle is mani- fested
by a frightful destruction of organisms, and principally young organisms not yet arrived at the age when they are able to reproduce themselves. It is caused, first, by the limitation of subsistence upon the surface of the globe ; secondly, by accidents, inclemency, cataclysms, diseases, parasites, etc., which assail living beings. It is not a battle open to the individuals of a single species, one against the other ; but, indeed, it is a blind fury to procure the subsistence furnished often by other species, and in this case it presents an active character ; or it is in a resistance to inclemency, etc., and in that case presents a passive character. The struggle for existence is, above all, the struggle against death. 1
This natural selection has as its result the survival of the fittest, repeated from generation to generation, and ending in the creation of new species. Darwin and Haeckel agree, espe- cially in regard to the most perfect organisms, plants, or ani- mals, among which cellular differentiation has reached a certain degree, that each animal and vegetable species was produced by natural selection only once, at a single moment of time, and at a single point in space. It is the center of creation of a species. The multiplicity and complexity of the conditions for these higher forms could with difficulty, according to Darwin and Haeckel, occur more than once.
- A. LAMCERE.
