THE FLY.

Northland Age, Volume VII, Issue 37, 13 May 1911, Page 2

THE FLY.

THE WORLD’B GREATEST MURDERER. Home remarkable ; statistics have Jrnt reached us, says “Science Sift•n 'B,“ from the health authorities of foreign city. It has been found that in the country concerned 75,000 children die each year from summer complaint “summer diarrhoea,” “summer dysentery,” 4,, cholera morbus,” and the like. These 75,000 children are murdered, for summer complaint is the house-fly’s crime ! Everybody has heard of summer complaint. Why does it become a plague 'in summer, rather than at other seasons ? Until very recently nobody knew why— though the supposition was that heat was the cause. Now, however, it is known that temperature has nothing directly to do with the matter. The house fly is the carrier of the malady. The hot season is the season of flics, t The germs that cause! the plague that kills the babies are borne and distributed by flies. The Insects introduce the germs into the milk or other food that infants eat, and the helpless little victims perish by myriads. There is no guesswork about this ; it is proved fact. It is an old story that breast-fed babies arc relatively immune to "summer complaints.” Up to now the reason why has been unknown — the supposition being that the constitution of the infant was stronger when the natural method of feeding was adopted. But the new knowledge shows that this theory was wholly in error. The breast-fed babies arc rarely attacked by the plague, because the flies cannot get a chance to contaminate their food. Among the by-products of domes lie life (l?"much filth, of one kind or another. It ought always to be covered in. pome way (for the very reason here suggested), and thus protected from access by insects. But, as a matter of fact it i * too commonly left exposed, and the .esult is that flies, which dearly love all kinds of nastiness, seek it, feed upon it, and lay their eggs in it, if it be of a character suitable for this last purpose. Such filth is fnll of virulent microbes—germs of kinds which, when introduced into the human body, rapidly multiply, if they find conditions favourable to their growth. The “food tube” of a young child appears commonly to afford them a suitable breeding ground. They propagate in it in great numbers, incidentally discharging large quantities of a specific poison ; high fever and other alarming symptoms ensue, and the child dies. “Summer complaint” says the doctor, shaking his head mornfully, as much as to say that the attack was of a common kind, yet too serious I for medical skill to defeat. But what caused it ? One miserable house fly. The statistics gathered by Prof. Fisher indicate that two years and four months might be added to man’s life if all the preventive cases of diarrhoea and enteritis were slitninated, two years more would be gained if the campaign against consumption were pushed a 3 vigorously as it might be, while but for the preventive cases of pneumonia, diptherif* and violence another three years might be saved. By far the greatest waste of human life attributable to any single cause is therefore seen to be due to the ravages of diarrhoea and enteritis, of which the house fly is known to be the principal dissemina'tor, and it follows that if the actij vities of that baneful insect were i curtailed human life would be accordingly increased. Indeed, it Is a simple calculation to show that upon this basis the fly nuisance is responsible for the loss of no less, than one hundred and seventy million years of 'human life, or four million human [lives of the present average length ! Even war would lose much of its jhorror with the disappearance of the : house fly. This fact has been clearly brought out in all of the wars of i recent times, which have been conducted under the surveillance of observing army doctors and hygienists. ;Thphoid and other contagious diseases have accounted for their thousands of lives where the bullets of the enemy have destroyed their hundreds, and that these diseases are spread by flies is no longer disputed by those who have observed sanitary

conditions in time of war. One of the most insidious aspects of the fly nuisance is the fact that the fly infects food without in any way rendering the article lees palatable to the consumer. A fly may deposit typhoid bacilli upon a cooked potato in sufficient quantities to infect a hundred men if it were possible for so many to partake of the one potato, and yet there would not be the slightest indication to the unfortunate whose lot it was to eat that particular potato that there was anything the matter with it. The question is often asked : Where do oil the flies come from 7 Accepting the conservative statement that one fly lays 120 eggs at a time, and that this brood of new flies produces another brood in three weeks, that fly might have 5,184,663,552,000,000,000 descendants from one season’s , batch of eggs. But the fly will lay many score batches of 120 eggs at a time during the season, and the total must be multiplied by those srotee 4 Thus the season begins with many

billions of flies and the total must be multiplied by those billions. The total number of flies, therefore, that might conceivably be hatched in a season, reaches an almost illimitable number. They would exceed the size of the whole earth in bulk. This catastrophe is prevented by uumer-

one causes, which keep down the number of flies. Flies come into the world full sized. If yew see small ones they belong to a different species from the common house fly. The eggs of the house fly are of a long, oval shape, opaque, a nd of a dull, chalky colour. Dr. Packard has observed a single house fly lay 120 eggs in fourteen hours. They were deposited | in stacks. Twenty-four hours after the completion of the laying, some had already hatched, and the rest very soon followed suit. In this case there was no nourishment at hand. If there had been the fecundity of the flies would perhaps have been much greater. The larvae exhibit a strange, instinctive intelligence even before they are hatched out. And. remember the more nourishment there is obtainable the more rapidly they will hatch; so, see that your home is kept clean and free from fly nutriment.