Parasitism : organic and social / by Jean Massart and Emile Vandervelde ; translated by William Macdonald ; revised by J. Arthur Thomson.

Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: Parasitism : organic and social / by Jean Massart and Emile Vandervelde ; translated by William Macdonald ; revised by J. Arthur Thomson. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    put forth in the direction of self-defence. The host sometimes contrives to make the parasite do him service. Those observations are equally true of social para- sitism, except as regards the reproductive function. We have found that the social parasite does not transmit his economic character by organic inheritance, and that the laws of reproduction play but a secondary part in keeping extant the different varieties of para- sites. The leading factor at work here is the imita- tive impulse. This fact suffices to explain why social pai’asitism does not result in such profound changes as the organic world displays. A man is not born a social parasite, but acquires that character in the course of his lifeffiistory; and, being an acquired character, it is not transmissible.1 Nevertheless, such modifications as do occur opei’ate in the same direction as those which are so well marked in organic nature. The society which is exploited by parasites becomes feeble; the parasitic individuals tend to degenerate. If the society is poorly or defectively organised, there is a free multiplication of the parasitic classes, and the 1 [The authors here adopt, without question, the belief of Weismann and others that characters acquired from function or environment during the lifetime of the individual are not trans- missible. But it is hardly proven.—TV.]