Morning journal and courier., 1883-07-24

The Victims of q Minute Parasitical Iu-
 ssct-The Discovery ofa Curious Micro seopfcEI Creature which Appears to
 Prey uPou the FIy's Head.
 .From the New York Times
 During the progress of the recent hot wave, by which the mortality of the city was so suddenly increased, phenomenon of curious interest to naturalists and etymolo- gists was developed by the unwonted temper ature It consisted in the outbreak of an extraordiny epidemic of brain disease among the house flies in certain parts of the city, caused b. the presence of minute parasitic insects in the tissues and vessels of that or gan, cases of which were demonstrated by post mortem dissection at the hands of one of our most indefatigable microscopic in quirers, who, during the heated term of the summer of 1876, first discovered and demon- strated the existence of the epidemic, and traced the vital history of the insect to whose irritating presence it is due. The subject is, for several reasons, one of more than ordina- ry interest to scientific men. In the first place, the insect concerned in the propaga- ton of what may be described as the first example of insanity in the insect kingdom that science has ever recorded is by far the
 minutest organism of that type that has yet been registered by entomologists, the head and trunk measuring from tip to tip less than one-twentieth of millimetre. In the second instance, it possesses certain remarkable peculiarities of structure, among which are a pair of sucking disks and two gullets, in place of the ordinary insect mouth and throat. Thirdly, in certain features of it's embryol- ogy, notably in the absence of any larval stage it allies the insect tribes directly with the larger infusoriums, and furnishes parti
 sans of Darwin's theory with 8 long sought connecting link
 As furnishing clues that may assist natura- lists ia obtaining specimens tho story of the
 xoek be of interest. In September, 1876, Dr. F.. G. Fairfield, who occupied suite of rooms at No. 80 Lexington avenue, noticed for several evenings in succession the frantic buzzing and plugging of scores of flies about the flame of an unshaded gas jet, and in the morning dozens of dead insects, being upon their backs, dotted the marble top of the bureau, one corner of which vertically beneath the burner. From cursory examine
 ton with a strong Coddington lens the dead insects did not appear to have suffered from contact with the flame, and this fact taken in connection with the frantic movements they exhibited previous to dropping led the discoVerer to institute 8 thorough exam ination with the aid of Quekett dissecting microscope A careful dis section of the trunk in several cases dis closed no cause of death, but when he came to remove the cranium of head that had been pickled in pure alcohol for several hours, LIS DIdIu, luS kldAu6 dG lAo root of the proboscis, and the cerebral mem branes and vessels were discovered to be densely crowded with parasites that were at first mistaken for infusoriums, bnt which, on applying power of two hundred diameterS,
 to the wonder and confusion of the discoy- erer, proved to be true representatives of the insect type. Guided by this curious discove- ry, many dlssections of dead flies were made in the course of the three or four evenings that followed, with a view to trace out the origin and life history of the fly pest, but some of the facts essential to form coher- ent narrative were still wanting when the ep- idemic subsided and although the doctor has been on the qui vive every summer for the last six years, the peculiar form of in sanity that decimated the flies of this city during the centennial year, and destroyed them by myriads, has not since made it's ap pearance, even in sporadic cases, until with 1 in the last few days. How far the disease extends, whether it will assume the epidemic form, and whether the present center of in- lection is one whose limits are very narrow, arc questions that can only be determined by directing the attention of naturalists in all parts of the city and country to the curious fact that the house fly is subject to periodl- cal epidemics of fatal brain disease caused by the presence in that organ of innumerable ln- sect parasites.
 These wonderful examples of the insect type are so inconceivably minute that a hun dred thousand could be packed in the era. nium of a mature fly, while in the last stages | of the disease they become so numerous in i the brain of the victim that they may, with a low magnifer, be readily mistaken fol nerve cells. When enlarged 300 or 400 di ameters the head is seen to be furnished l with pair of seyen-jointed antenn@, termi l mating in needle. like processes, keen and
 flexible. Two sucking disks, each leading tc
 a separate gullet, appear upon the inferior
 lateral surfaces of the head. The gullets ex
 tend backward and inward until they unite
 in 8 common digestive cavity scarcely capa