“The immunity of the water flea, due to the help of its phagocytes, is an example of natural immunity ... for, once the wandering cells have not swallowed the yeast spore at the moment of its penetration into the body, the yeast germinates ... secretes a poison which drives the phagocytes back not only, but kills them by dissolving them completely.” IV Then Metchnikoff went to see if this same battle took place in frogs and rabbits, and suddenly, in 1886, the Russian people were thrilled by Pasteur’s saving of sixteen of their folk from the bite of the mad wolf. The good people of Odessa and the farmers of the Zemstvo round about gave thanks to God, hurrahs for Pasteur, and a mighty purse of roubles for a laboratory to be started at once in Odessa. And Metchnikoff was appointed Scientific Director of the new Institute--for had not this man (they forgot for a moment he was Jewish) studied in all the Universities of Europe, and had he not lectured learnedly to the doctors of Odessa, telling about the phagocytes of the blood, which gobble microbes? “Who knows?” you can hear the people saying. “Maybe in our new Institute, Professor Metchnikoff can train these little phagocytes to gobble up all microbes?” Metchnikoff accepted the position, but told the authorities, shrewdly: “I am only a theoretician; I am overwhelmed with researches--some one else will have to be trained to make vaccines, to do the practical work.” Nobody in Odessa knew anything about microbe hunting then, so Metchnikoff’s friend, Doctor Gamaléia, was sent to the Pasteur Institute in Paris posthaste. The citizens were anxious to begin to be prevented from having diseases; they bawled for vaccines. So Gamaléia, after a little while in Paris, where he watched Roux and Pasteur and learned a great deal from them, but not quite enough--this Gamaléia came back and started to make anthrax vaccines for the sheep of the Zemstvo, and rabies vaccines for the people of the town. “All should now go very well!” cried Metchnikoff (he knew nothing of the nasty tricks virulent microbes can play) and he retired to his theoretical fastnesses to grapple with rabbits and dogs and monkeys, to see if their phagocytes would swallow the microbes of consumption and relapsing fever and erysipelas. Scientific papers vomited from his laboratory, and the searchers of Europe began to be excited by the discoveries of this strange genius in the south of Russia. But he began to have troubles with his theory, for dogs and rabbits and monkeys--alas--are not transparent, like water fleas....