The daily morning journal and courier., 1898-08-17

when confined in the warm season to a small receptacle, not at all tenacious or life. Owing to this fact, 1t has been im- nossible to ascertain the length of life of a fly.
 The experiments proved that horse manure is the favored breeding-place of the houseiy. Though eggs were laid upon COW manure by the female insects in confinement the larvae did not ma ture The housefy can rarely be in duced to lay it's eggs upon anything but horse manure and COW manure, and it's preference for the former is very marked. But, though it will lay freely upon undisturbed horse manure, 1t will not do so if the substance is spread out. Observations show that there is abun- dance of time for the development of twelve or thirteen generations of flies in a climate like that of New York eve- ry summer.
 The number of eggs laid by female housefy averages one hundred and twenty. and the enormous swarms in which the insects occur are thus plain ly accounted for. In order to ascertain the numbers in which the larvae of this species occur in horse manure piles, a quarter of a pound of rather well in fested horse manure was taken on Au- gust of last year, and in it were counted one hundred and sixty larvae and one hundred and forty-six puparia. This would make about two thousand flies to the pound of manure. It is not to be supposed, however that this is the limit 1nasmuch as two hundred pu- s,, los fhn1, 0tJ- bic inch of manure taken from a spot two inches below the surface of the pile, where the grubs had congregated in immense numbers.
 The most obvious method of defence against housefies is to do away with their breeding places, l. e., the manure piles in and about stables. A single stable in which a horse is kept will sup ply housefies for large neighborhood. People living in agricultural communi- ties will probably never be rid of the pest, but in cities, with better methods of disposing of garbage, and with les- sening of the number of horses and sta- bles consequent upon the introduction of electric street-cars, bicycles and horseless carriages, the time may come, dUu UtlOlG very iOuS, WlSl WllluOW screens will be discarded.
 The prompt gathering of horse ma- nure, which may be sprinkled with chemicals or kept in specially prepared receptacles, would greatly abate the fly nuisance. Ordinances ought to be passed in every city compelling the adoption of some such methods. Abso- lute cleanliness, even under existing circumstances, will always result in a diminution of the numbers of the in sects, and, in fact, the housefy is less attracted to the premises of what is known as the old-fashioned housekeep- CT than to those that are kept with a less painstaking regard for the absence of dirt.
 Fortunately, the housef1y has some natural enemies. The common house centipede destroys it in considerable numbers. It is subject to attacks by several kinds of parasitic insects, and is assailed by predatory beetles. The most effective enemy, however. is a fungous disease, which carries off mill lions.
 It must be acknowledged that Musca domestica is a remarkably intelligent animal. Among insects he is what the sparrow is among birds-a parasite on man, living at his expense and depend- ing upon him for protection to a great extent. Both fly and spaErow owe