Repository: UIHistories Project: Board of Trustees Minutes - 1884 [PAGE 83]

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87 •contagious character. In one case the affected larvae became restless, ceased eating, the skin assumed a decidedly yellowish tint and ultimately became very tender and easily ruptured, while the blood, unusually copious, was thin and yellow instead of its normal limpid or grayish color. Other larvae became sluggish, continued to eat, but consumed only a small quantity of food, the body gradually became flaccid, the skin wrinkled and tough and the color a grayish or leaden tint, and finally nearly black. These, hours or even one or two days before their death, adhered by their prolegs, or some of them, to a support, and remained quiet, at length only showing signs of vitality when touched, and at last dying while still firmly anchored to. the limb or other object upon which they rested. After, and for some time before, death the flaccid body hung directly downward from the point of attachment. If this latter happened to be near the middle of the body, the two ends hung down, the parts nearly parallel with each other. From these dead and blackened worms a decided and characteristic odor of putrescence was perceptible, tainting, when ^numerous, the air of the well ventilated room. On microscopic examination, the blood of those last described was found to contain great numbers of a Bacillus, a genus of bacteria which is now known to contain several species of true disease producers. To obtain the blood for examination free from the other fluids of the body, the end of one of the prolegs was snipped off with a pair of scissors, when a drop exuded and was at once secured upon a glass slide. The yellowish blood from those first described seemed perfectly free from living organisms so far ,as could be ascertained by microscopic examination; yet in one case out of the numerous worms examined, the same or similar organisms to those above noted were found. These, or similar, organisms were, however, found in the alimentary canal of all the worms examined which were supposed to be affected with these contagious maladies. Packages of both kinds were several times sent Professor Forbes, who, as is well known, as State Entomologist has made a special study of the diseases of insects, and especially of those of a contagious character; the reports of his examinations correspond with that above, except that no organisms were certainly Jound in the blood of any of the diseased but still living worms, in his attempts to cultivate the intestinal organisms, as well as to test the blood in nutrient fluids, another organism belonging to the genus Micrococcus (also included among bacteria) was constantly found, and this, upon trial, proved destructive to other caterpillars in a manner similar to the disease or diseases of the silk worm. Professor Forbes inclines to the opinion that the two classes of symptoms as above given really belong to one disease, due to one specific organism, and that the apparent differences, marked as they seem, are on account of the parts of the caterpillar's body specially affected. This difference may be due simply to the mode of communication of the disease agents, and the organs of the# body first reached. The presence of the Bacillus in the blood of the specimens examined by us may be accounted for, perhaps, by the fact that in some cases the alimentary canal is perforated either by rupture or