206 THE AMERICAN JOURNAL OF SOCIOLOGY
esting train of effects which leads from custom to law, from the gentile to the civil organization, from the minor to the larger social division of labor, resulting in the formation of a new people on a much higher plane of social evolution, has been so admirably worked out by Gumplowicz, 1 Ratzenhofer, 2 and Ward 8 that it is unnecessary to set it forth here.
VIII. Alteration in the environment. Upborne by vegetable and animal life, human societies are exposed to disturbances aris- ing from changes in the worlds of flora and fauna. Plant encroaches upon or drives out plant, animal presses back or exterminates animal. Fishing communities are profoundly affected by mysterious vicissitudes in the run of food-fishes. Hunters and agriculturists have trying experiences which show how unstable is the medium on which they float. Consider how in our own day the phylloxera, the rinderpest, the foot-and-mouth disease, and the boll-wevil cause economic crises which may be reflected in institutions. Those migrations of micro-organisms which gave rise to the Black Death, the Asiatic cholera, and the bubonic plague have been more fateful perhaps than the inva- sions of Huns or Tartars. The fearful pest which under the Antonines wiped out half the population of the Roman Empire made it a shell easy for the barbarians to smash into. The Black Death of 1349, by making laborers scarce and dear, gave rise to the long series of Statutes of Laborers aiming to re-attach the cultivators to the soil. A permanent extension of the adminis- tration of the state has often dated from a sudden calamity a pestilence, a famine, a murrain, a flood, or a tempest which, paralyzing private efforts, has caused application for state aid. The vast machinery of the Public Health Department in England has rapidly grown up in consequence of the cholera visitations in the middle of the last century. How many lines of influence from the abolition of the Corn Laws to the Hibernian conquest of American cities radiate from the Irish famine of 1845-46!
To sum up the results of these three papers in Social Dynamics :
1 Kassenkanpf, pp. 218-63. ' Sotiologi sche Erkenntniss, pp. 156-64.
' Pure Sociology, pp. 305-15.
