THE ASYMMETRY OF THE CYCLE OF LIFE 145
made in some other fishes and amphibians, and especially in the smooth skate, Raja batis.* The transient nervous apparatus of ganglion cells and nerve fibres in the skate development functioned for a time, for about three months from the start out the total of circa seventeen, and then quite suddenly began to -lade away, and to undergo a slow but sure degeneration.
The two nervous systems crop up again and again in my published writings since 1888, and, as indicating the import long attached to this antithesis, I find myself writing in 1905 a paper, “The Cancer Problem,”** opening with a recital of some of the facts in the history of the transient ganglion cells. All my original work, from 1888 down to to-day, is impregnated with facts concerning the two nervous systems, and the antithesis underlying them.. The discovery of that antithesis has impelled and influenced all my work since that time.
With the termination of the period of research marked by the publication of “The Interlude of Cancer,” I recognized that my original work was approaching and tending to converge to the work of Pasteur. The researches had led finally into problems of the chemistry of the ferments, and especially of the extracellular enzymes. trypsin and amylopsin. It is not too much to say that Pasteur had founded a science of the ferments. True, he laboured for many years at the problems of Intracellular enzymes, such as the yeast organism, the mould, Penicillium, etc., and the enzymes trypsin and
* Beard. J. “The Early Development of Lepidosteus osseus” Proc. Roy. Soc. Lond., 1889, vol. xlvi., pp. 108-118 . Ibid: The History of a Transient Nervous Apparatus in Certain Ichthyopsida: An Account of the Development and Degeneration of Ganglion Cells and Nerve Fibres, Part I., Raja batis,”Zool. Jahrb. Morph. Abteil . 1896, vol. viii., pp. 1-106, 8 plates.
** Ibid:” The Cancer Problem,” Lancet, February 4, 1905.