He held a volume of pathological anatomy in the red ray from his table-lamp, and conned its text and numerous reproductions. He read of the existence of parasitic cell-juncture and of infectious tumours. These were forms of tissue⁠—and very luxuriant forms too⁠—produced by foreign cell-bodies in an organism which had proved receptive to them, and in some way or other⁠—one must probably say perversely⁠—had offered them peculiarly favourable conditions. It was not so much that the parasite took away nourishment from the surrounding tissues, as that, in the process of building up and breaking down which went on in it as in every other cell, it produced organic combinations which were extraordinarily toxic⁠—undeniably destructive⁠—to the cells where it had been entertained. They had found out how to isolate the toxin from a number of microorganisms and produce it in concentrated form; and it was amazing to see what small doses of this substance, which simply belonged to a group of protein combinations, could, when introduced into the circulation of an animal, produce symptoms of acute poisoning and rapid degeneration. The outward sign of this inward decay was a growth of tissue, the pathological tumour, which was the reaction of the cells to the stimulus of the foreign bacilli.