THE ASYMMETRY OF THE CYCLE OF LIFE 147
seriously contradict one of mine.” In passing, be it remarked that every word of this passage might be applied to happenings at the present time regarding the problems of cancer. Then Pasteur explained how the whole series of his marvellous discoveries, chemical, bacteriological, or medical, hung together and formed a complete chain—e.g., anthrax, the pure fermentation of beer, the acetification of vinegar, the diseases of vines, the means of preventing them, and, lastly, going back seventeen years, the first link in the chain of discoveries, that of the double tartrate crystals, and the facts concerning their dimorphism.* “ The best proof that an observer is right is the uninterrupted fruitfulness of his work.”**
Pasteur worked for seventeen years at his chain of discoveries; it was in 1907 nineteen years since the first link of my chain was forged. The thread each of us obtained at the start was the discovery of the antithesis of two things: he, the two kinds of tartrate crystals; I, the two distinct and separate nervous systems in the life-cycle of a fish.
Why should all this be? What connection was there between the two facts, which, apparently, were as wide apart as the poles? The evident fact has already been referred to, that in 1904 the two independent lines of work were converging, but it was more than this. It was a union. The thing which impelled Pasteur’s work incited mine also. The antithesis he discovered was in
* Pasteur, Louis: “De Ia Dissymmétrie Moléculaire des Produits Organiques Naturels.” Lecon professée devant la Société Chimique, 1860.
** This chain-like character of Pasteur’s researches has been commented upon by others—thus by Miall (“History of Biology.” 1911)—but I doubt whether any of the commentators have grasped the true significance of Pasteur’s meaning.