Large abscesses form as the result of the coalescence of small ones, and by the time the disease is recognized extensive destruction and loss of substance may have taken place. In man it is not alone about the mouth that the disease is noted, although primary lesion here is by no means infrequent. It leads to affections similar to that already spoken of in cattle, with a progressive infiltration and breaking down, including actual necrosis of bone, etc. The pus will escape at various points, and may give to the surface an appearance as of many craters with a central cause. When the disease has involved the lung, either directly or indirectly, the fungi and the calcareous particles may be found in the sputum. Should there be suspicion of this involvement, the sputum should always be examined. Even in the heart substance tumors of this same character have been found. The first case noted in man had undergone extensive vertebral caries. Intestinal infection is possible, in which case multiple lesions will form in the intestinal walls, which may contract adhesions to the abdominal parietes and discharge externally through them. The appendix has been found involved in such lesions. Infection of the skin has also been described, though this occurs more rarely. =Diagnosis.=--Actinomycotic lesions have been _mistaken for cancer_, _sarcoma_, _tuberculosis_, _syphilis_, etc. In man it will always be characterized by more or less suppuration, and in the purulent discharge from the infected focus the yellow calcareous particles should enable recognition of this disease at once. =Prognosis.=--As long as the focus is accessible it is a purely local matter, and prognosis is as favorable as in local tuberculosis; but, inasmuch as in many cases infection has proceeded to a point where the surgeon cannot safely follow it, prognosis must be guarded. Actinomycosis is free from acute manifestations, for the main part free from pain, pursues a chronic course, and is characterized, as are the other slow infections, by progressive emaciation, prostration, etc. As it is essentially a chronic condition, time is afforded for careful study in doubtful cases, for microscopic examination, etc. =Treatment.=--This must consist of extirpation of all infected tissues and areas. If this can be done thoroughly there is a prospect of positive cure. Free incision, wide dissection, the use of the actual cautery, etc., are always called for in these cases. If it involves the tongue alone, there is an excellent prospect; if but a portion of the jaw is involved, a complete excision of one-half or more may be followed by excellent results. If, however, the lung, liver, vertebrae, or other vital and inaccessible parts are involved, surgical measures may afford amelioration, but can hardly be expected to cure.