In _chronic cases_ the anæmia is prominent. The clot is soft, relatively small, elastic and black, the serum is relatively very abundant and pale. The red globules are greatly reduced in numbers, and there are a number of giant cells which stain deeply as in chlorosis. The lymph glands are usually enlarged, softened and slightly congested but rarely the seat of blood extravasation. The tissues generally are pallid, soft and shrunken. There is a marked absence of subcutaneous and intermuscular fat, while the connective tissue is more or less infiltrated with a transparent, watery lymph. The serous cavities usually contain more than the normal amount of fluid, transparent or straw-colored, and with few globules or granules. Congestions and even shreds of false membrane are sometimes present on the serosa. In some cases the lungs and bronchia are the seat of inflammatory exudates, causing nodular consolidations of from one-half to one inch in diameter. Not unfrequently the lungs show strongylosis as the fourth stomach shows strongylus contortus, the small intestines strongylus filicollis, tæniae (expansa, fimbriata, etc.), the large intestines æsophagostoma Columbiana, and tricocephalus affinis, and the gall ducts distoma hepaticum and distoma lanceolatum. In these chronic cases the spleen is usually shrunken, and the liver firm, sometimes even cirrhotic. _Mortality._ The acute cases are usually fatal. Those that assume a chronic form, if free from local lesions in important organs, well-fed, and, above all, kept in the open air, and changed to a different pasture, tend largely to recovery. _Prevention._ The propagation of the infection from animal to animal is slow and somewhat uncertain, and when introduced by the purchase of a new ram or other animal, it may take a considerable time to affect the stock extensively, but for this reason, and because an apparently sound sheep may harbor the germ, it is difficult to oppose it successfully by segregation. All the same, it is desirable to take all possible precautions against its advent, and among these, the exclusion of strange sheep from noninfected pastures and flocks. When the time comes to make an outcross from the home strain, the ram must be selected not only for his pedigree and individual qualities, but no less for the soundness of the flock from which he is taken. If the lambs of that flock have been decimated by disease, the best blue blood, and most faultless form should not tempt the flockmaster. He should be rejected in favor of one taken from a flock that is above suspicion. It matters little if it can be plausibly argued that the mortality came from worms of the lungs, liver, or digestive organs; these in themselves may soon ruin any flock, but they, too, often coexist with the microbe of infectious septicæmia, and, when this is the case, they prepare the system and open a way for its invasion.