for new cases caused by mosquitos that might have bitten this man; and tracing back the source of his infection to some earlier and perhaps hitherto undiscovered case.
This would have been a well-nigh impossible task if the yellow-fever mosquito had been as strong on the wing as the more harmless species we know so well at home, most of whom can fly for miles with a favorable breeze. Fortunately, the Stegomyia is a feeble creature, usually living in or about houses, and rarely flying more than a hundred yards from its birthplace in some stagnant pool. The favorite breeding-places of these insects in Panama City were the rain-water barrels and cisterns, which were first screened and afterwards destroyed when the new waterworks were finished.
The old waterworks consisted of two or three large Spanish wells, that received most of the drainage from the graveyard, and a few carts, from which the man who owned the graveyard used to peddle this water through the streets, for five cents a gallon. It was much better for his business than for the people who drank it. The Americans stopped this, and piped in good water from a reservoir made by damming the Rio Grande. There was a great celebration on the Fourth of July, 1905, when the water was turned on in the Cathedral Plaza. The President, and the Governor, and all the other dignitaries, both Panamanian and American, attended a solemn high Mass in the cathedral, and at the elevation of the Host and the stroke of noon, the water was sent spurting into the air outside, and the Panamanian Republican Band struck up what it thought was the American national
