Grassi was as persistent as Ronald Ross had been erratic. He plugged up every little hole in his theory that anopheles is the one special and particular mosquito to bring malaria to men. By a hundred air-tight experiments he proved the malaria of birds could not be carried by the mosquitoes who brought it to men and that the malaria of men could never be strewn abroad by the mosquitoes who brought it to birds. Nothing was too much trouble for this Battista Grassi! He knew as much about the habits and customs and traditions of those zanzarone as if he himself were a mosquito and the king and ruler of mosquitoes.... VII What is more, Battista Grassi was a practical man, and as I have said, an excessively patriotic man. He wanted to see his discovery do well by Italy, for he loved his Italy faithfully and violently. His experiments were no sooner finished, the last good strong nail was no sooner driven into the house of his case against the anopheles, than he began telling people, and writing in newspapers, and preaching--you might almost say he went about, bellowing till he bored everybody: “Keep away the zanzarone and in a few years Italy will be free from malaria!” He became a fanatic on the best ways to kill anopheles: he was indignant (that man had no sense of humor!) because townspeople insisted on strolling through their streets in the dusk. “How can you be so foolish as to walk in the twilight?” Grassi asked them. “That is the very time when the malaria mosquito is waiting for you.” He was the very type of the silly sanitarian. “Don’t go out in the warm evenings,” he told every one, “unless you wear heavy cotton gloves and veils!” (Imagine young Italians making love in heavy cotton gloves and veils.) So there was a good deal of sniggering at this professor who had become a violent missionary against the zanzarone. But Battista Grassi was a practical man! “One family, staying free from the tortures of malaria--that would be worth ten years of preaching--I’ll have to _show_ them!” he muttered. So, in 1900, after his grinding experiments of 1898 and ’99, this tough man set out to “show them.” He went down into the worst malaria region of Italy, along the railroad line that ran through the plain of Capaccio. It was high summer. It was deadly summer there, and every summer the poor wretches of railroad workers, miserable farmers whose blood was gutted by the malaria poison, would leave that plain, at the cost of their jobs, at the cost of food, at the risk of starvation--to the hills to flee the malaria. And every summer from the swamps at twilight swarmed the malignant hosts of female zanzarone; at each hot dusk they made their meals and did their murders, and in the night, bellies full of blood, they sang back to their marshes, to marry and lay eggs and hatch out thousands more of their kind.