The changes occurring in the _liver_ were not of striking account. Cloudy swelling was observed 13 times, usually of moderate grade. The usual appearances with enlargement of the organ, bulging of the parenchyma on section and a dull gray cut surface were all that could be found. The one case with icterus was the only one in which the natural discharge of bile from the liver was interfered with through the swelling. Even in this case the obstruction to the outflow of bile in the small channels was not demonstrable in the microscopic sections, nor was there evidence of unusual bile staining of the liver-points suggesting the possible origin of the icterus in an unusual hemolysis. On no occasion did we meet with recent inflammatory reactions in the gall bladder or bile ducts, and we have no evidence that the organisms of the infection are discharged from the body by these routes. The cloudy swelling of the liver was accompanied by slight œdema of these tissues in seven cases; and in six instances focal necroses were observed. These focal necroses were similar in appearance to those seen in typhoid fever, but were much less frequent in the tissue. Only careful search revealed isolated pinhead gray dots with depressed centers. They were most commonly in the mid-zone of the lobule, and in the early stage were without inflammatory reaction. Subsequently, leucocytes infiltrated the area, but not in an amount to form pus. Bacteria were never demonstrated in the areas of focal necrosis. Four cases showed old adhesions about the gall bladder and in one a gall stone was present.

Lesions of the _pancreas_ were not encountered. In a few cases the lymph glands about the head of the pancreas were slightly enlarged.

Studies on Epidemic Influenza — Part 208

The _spleen_ showed relatively little reaction and in only two cases was it enlarged. Fourteen times a diagnosis of acute splenitis was made on examination of the gross specimen. This diagnosis rested upon the finding of a swollen spleen with tense capsule and with a dark bulging pulp. The Malpighian bodies were usually in part or completely obliterated, though in a few instances these grayish nodules seemed even larger than normal. These spleens contained an excess of blood within the pulp. In one case several isolated areas appeared hemorrhagic as if a local rupture of the tissues had occurred. The microscopic examination of these specimens showed mainly a marked congestion of the sinusoids, a diminution in the size of the lymphoid corpuscles and some increase in the number of leucocytes within the blood spaces and reticulum. Only occasionally did we observe a proliferative reaction of the large mononuclear cells lying in the reticulum. This proliferation was not sufficiently marked nor uniformly present to be considered as characteristic. We did not find abnormal deposition of blood pigment indicating an unusual destruction of red blood cells within the spleen. It is interesting to note that 5 of the 32 cases showed obsolete miliary tubercles in the spleen.

Studies on Epidemic Influenza — Part 208