2. The Analogistic Tradition from Anaximander to Bonnet

1. Events in the second half of the cycle have won a place for Empedocles among the forerunners of evolution. As love begins to amalgamate the ele- ments, scattered parts of bodies form and these join in a variety of combina- tions. A sort of " natural selection" then acts to preserve the favorable combi- nations. I regard any comparison between this scheme and later evolutionary thinking as purely gratuitous; Empedocles' system, needless to say, was for another time and another purpose.

2. Meyer (1935, p. 382) also states that Hunter's illustrations for the devel- opment of the chick have never been fully published; yet they are included in Owen (1841).

3. Adelmann (1966) has argued that Malpighi's position lay neither in the camp of evolution or epigenesis (his late seventeenth-century works predated the explicit formulations of a predominantly eighteenth-century debate). Yet he was generally cited, by Haller, for instance, as a supporter of preforma- tionism.

4. I do not wish to imply, of course, that preformationism was without its difficulties, or that its debate with epigenesis revolved only around conflicting philosophies. Preformationism faced a series of empirical dilemmas: If the embryo is preformed in the egg, what is the role of the sperm? If the sperm merely triggers the growth of a homunculus, how can the intermediate form of a mule be explained? Bonnet regarded this as a telling point and argued weakly: "This production already existed in miniature, but in the form of a horse in the ovaries of the mare. How was this horse metamorphosed? In par- ticular, where did its long ears come from? . . . I say that elements of the sem- inal fluid acted on those of the germ; the semen of the ass contains more

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