210 THE STRUCTURE OF EVOLUTIONARY THEORY
An unbiassed and more deeply probing conception of organic individuality
shows that these "true" or absolute individuals are, in fact, only relative...
Although these "true" individuals are, in most higher plants and
coelenterates, only the subordinate components of a higher-standing unity
(the colony), nonetheless the individuality of humans and higher animals
leads us to the erroneous conception that morphological individuals of the
fifth order are the "true" organic individuals. This concept has become so
general, and has been so strongly fixed in both scientific and vernacular
consciousness, that we must mark it as the major source of the numerous
and varied interpretations and debates that prevail on the subject of organic
individuality.Haeckel's concept of structural levels and the non-distinctive status of organisms
entered Weismann's argument in two crucial places—first, very generally, when
Weismann used the same style of thinking to establish a hierarchy of (hypothetical)
entities as the physical bearers of heredity within germ cells (see p. 214); and,
second, quite specifically, when Weismann invoked Haeckel's six-part hierarchy
(1896, p. 42) to argue that the struggle for existence starts within germ cells, but
then extends up through all Haeckelian categories to colonies at the top.
Roux's theory of intracorporeal struggle
Wilhelm Roux's Der Kampf der Theile im Organismus evoked a wide range of
reactions. Roux's teacher, Gustav Schwalbe, warned him against ever publishing
such a "philosophical" book again. Haeckel, another teacher, liked the work for its
consonance with his own ideas, while Darwin himself, during the last year of his
life, became greatly intrigued, writing to G. J. Romanes on April 16, 1881:
Dr. Roux has sent me a book just published by him ... It is full of reasoning,
and this in German is very difficult for me, so that I have only skimmed
through each page; here and there reading with a little more care. As far as I
can imperfectly judge, it is the most important book on Evolution which
has appeared for some time ... Roux argues that there is a struggle going on
within every organism between the organic molecules, the cells and the
organs ... If you read it, and are struck with it (but I may be wholly
mistaken about its value), you would do a public service by analyzing and
criticizing it in 'Nature' (in F. Darwin, 1887, vol. 3, p. 244).(Note how, contrary to the prevalent historical myth of the aged Darwin as the
reclusive "sage of Down," he actually (and actively) kept his ears alert, and his
fingers right on the pulse of evolutionary debate. Romanes represented just one
among several younger colleagues and supporters whom Darwin often recruited,
both overtly and nonsubtly, to carry forth his interests in both the public and the
professional arena.)