A papilloma has been observed in wild cottontail rabbits and has been found to be transmissible to both wild and domestic rabbits. The clinical and pathological pictures of the condition have been described. It has been found that the causative agent is readily filtrable through Berkefeld but not regularly through Seitz filters, that it stores well in glycerol, that it is still active after heating to 67°C. for 30 minutes, but not after heating to 70°C., and that it exhibits a marked tropism for cutaneous epithelium. The activities and properties of the papilloma-producing agent warrant its classification as a filtrable virus. Rabbits carrying experimentally produced papillomata are partially or completely immune to reinfection and, furthermore, their sera partially or completely neutralize the causative virus. The disease is transmissible in series through wild rabbits and virus of wild rabbit origin is readily transmissible to domestic rabbits, producing in this species papillomata identical in appearance with those found in wild rabbits. However, the condition is not transmissible in series through domestic rabbits. The possible significance of this observation has been discussed. The virus of infectious papillomatosis is not related immunologically to either the virus of infectious fibroma or to that of infectious myxoma of rabbits.

1. It has been possible to demonstrate, in Berkefeld filtrates of infectious material from experimental cases of swine influenza, a virus which when administered intranasally to susceptible swine induced a mild, usually afebrile illness of short duration. The changes in the respiratory tract resembled those in swine influenza but were usually much less extensive. When the filtrable virus was mixed with pure cultures of H. influenzae suis and administered to swine a disease identical clinically and pathologically with swine influenza was induced. The data presented indicate that the filtrable virus of swine influenza and H. influenzae suis act in concert to produce swine influenza and that neither alone is capable of inducing the disease. 2. One attack of swine influenza usually renders an animal immune to reinfection. Blood serum from an animal made immune in this way neutralizes infectious material from swine influenza in vitro, as shown by the failure of the mixture to produce disease in a susceptible animal. 3. The virus can be stored in a dried state or in glycerol for several weeks at least. In one instance dried material apparently retained both the virus and H. influenzas suis in viable form for a period of 54 days. 4. Fatal cases of experimental swine influenza have been observed in which H. influenzae suis was the only organism that could be cultivated from the respiratory tract. 5. Attention has been called to some features of marked similarity between epizootic swine influenzae and epidemic influenzae in man.

This paper deals with a tumor-like condition in a wild cottontail rabbit (genus Sylvilagus) and its experimental transmission to domestic rabbits (genus Oryctolagus). The term "tumor" is used in its broadest sense to indicate a local swelling consisting of a mass of new tissue. Description of the Original MaterialThree prominent subcutaneous tumors were observed in a wild cottontail rabbit shot in Nov., 1931. The animal was taken immediately to the laboratory and autopsied. Two of the tumors, on the inner and upper aspect of the left hind foot, were egg-shaped and approximately 1.5 x 2 cm. in diameter. The other, which was somewhat larger, was on the left fore leg just below the shoulder. There were no overlying surface abrasions and, although the tumors seemed to be firmly attached to the skin, they were freely movable over the underlying solid skeletal structures.On section each of the tumors was found tobe white, firm, moist, and free from evident necrotic areas. They cut as though fibrous, the cut surface bulged, and the general appearance was that of a fibroma. There was nothing of significance found in the remainder of the autopsy. The condition of the animal appeared good, it was not in the least emaciated, and there were no evidences of metastases in the regional lymph nodes or the organs.Pieces of each of the tumors were removed aseptically to use in inoculating laboratory rabbits and the remainder was stored in 50 per cent glycerol or put in fixative for histological study.Histologically the three tumors seemed to be identical. The main mass was composed of connective tissue cells; many of these resembled fibroblasts and were spindle or polygonal in shape with abundant cytoplasm and large round or oval nuclei. Most of the cells, however, were of the small thin connective tissue type with scant cytoplasm and thin spindle-shaped nuclei (Fig. 1). Mitotic figures were scarce. The arrangement of the cells was rather compact and irregular; in general the long axes were perpendicular to the base of the tumor. 793 on

Swine influenza has been induced in pigs by the intranasal instillation of material from spontaneous cases of the disease as occurring epizootically in eastern Iowa. The experimental disease has the same features as the epizootic. It has been maintained for study by serial passages accomplished either by intranasal instillation or by pen contact. Eight strains of the virus have been established experimentally during three epizootic periods. The clinical disease induced by these eight strains has been in general the same although its severity and mortality have varied. The principal features of the pathology of swine influenza are an exudative bronchitis accompanied by marked damage of the bronchial epithelium and its cilia, a peribronchial round cell infiltration, and massive pulmonary atelectasis. The latter is modified somewhat by a round cell infiltration of the alveolar walls. The lymph nodes, especially the cervical and mediastinal ones, are hyperplastic and edematous. There is usually a mild to moderate, acute splenic tumor. The mucosa of the stomach and colon is congested. The pneumonia following swine influenza is, characteristically, lobular in type and of the same general distribution as the atelectasis. The non-pneumonic areas of lung are extremely edematous and congested.

A circumscribed natural outbreak of a highly fatal disease of deer, which we have designated epizootic hemorrhagic disease (EHD), has been studied. The disease has proven readily transmissible in deer but not in other experimental or domestic animals tested, nor in embryonating eggs or deer kidney cell cultures. The causative agent is a virus which is readily filterable and is capable of storage, either frozen or in glycerol, for relatively long periods of time. It produces a solid immunity in the few animals that survive and the blood sera of such convalescent animals contain virus-neutralizing antibodies. The disease is one in which large and small hemorrhages occur in both the viscera and skeletal structures of the body, as well as in the subcutaneous tissues. It is probably the same as one known popularly in the southeastern United States as "black tongue" of deer. It is unrelated to epidemic hemorrhagic fever of man or to the disease caused in horses by the equine arteritis virus. At least two serologically different types of EHD virus exist. The New Jersey strain is of greater lethality for experimental deer than the serologically different one obtained from an outbreak that occurred in South Dakota a year after the New Jersey epizootic.