Page:Popular Science Monthly Volume 66.djvu/289

Rh used to fill the small deep holes that would naturally drain most slowly. Toward the end of the task in April, it became a race between the ditchers and the insects, which were beginning to pupate. The ditchers won and the last pool was drained before the first adult mosquito issued. It was interesting to watch a new ditch just opened into tide water, flowing in a steady stream toward the outlet and carrying a surface cargo of wrigglers and pupæ; and yet more interesting was it to see the 'killies' at the ditch mouth, taking care of every specimen that came out and gradually running up the ditch to meet them. On these hundreds of acres of meadow not one of the

millions of mosquito larvæ came to maturity. On the marshes to the north and south where no work was done, the mosquito output was phenomenal and the early summer of 1904 will be long remembered. Not only the nearby cities and towns were sufferers, but the insects actually crossed both ridges of the Orange Mountains in their travels to the west, and swarmed in the hills about Paterson to the north. And in all this the Shrewsbury River country was practically free from mosquitoes and remained so all summer! There were some local fresh-water species that proved troublesome later in the season; but these were dealt with as fast as their breeding places were located. The marsh mosquitoes that had been the pest of previous years were conspicuous by their absence. A yet greater work was done by the City of Newark, where 3,500 acres of salt marsh were dealt with. No results were apparent in 1904, because the heavy early broods were allowed to develop unchecked; but the marsh is now dry except in a