Injection of oil of turpentine into the peritoneal cavity of a dog calls forth immediately an exudate of fluid from the surrounding tissues. The amount of fluid reaches the maximum on the third day and has practically disappeared on the fifth day.
The cell content of this fluid is very small at first, but increases rapidly. The type of the predominating cells also changes. In the early exudate the small mononuclear cells are numerous and the large mononuclears few. Later the number of large mononuclear cells is increased and ultimately the polymorphonuclear cells preponderate. Various forms of atypical cells also occur.
Much of the fluid and many of the cells are removed by way of the thoracic duct. The counts of the cells in the thoracic duct and the estimates based on these indicate that the duct does not remove all of the fluid or cells from the peritoneal cavity. Much fluid is probably taken back directly into the blood, as are many of the cells. Some of the cells make their way to the lymph nodes, while many perhaps undergo complete autolysis in the serous cavity.
The polymorphonuclear cells do not enter the thoracic duct in great numbers. Examination of the lymph from the thoracic duct in the case of my dogs showed the types of cells that are usually found there.
The variation in small mononuclear cells is so related to the cell content of the peritoneal effusion as to indicate that the supply in the blood is maintained from this source. The form and staining qualities of the cells indicate that many of the small mononuclear cells are returned to the thoracic duct.
The ratio of polymorphonuclear cells present in the lymph bears no definite relation to the other features of the process. The transitional cells were increased in number and in their ratio to other cells. The increase in the transitional types accompanies an increase in large mononuclear cells and a decrease in small mononuclears.
None of the atypical forms of cells found in the effusion were seen in the lymph.
The number of eosinophils is without apparent relation to the other features of the process.
No polymorphonuclear cells containing the pigment injected were found in the lymph of the thoracic duct, and the number of mononuclear cells containing pigment was small. Much pigment was deposited in the lymph nodes. Detailed and definite conclusions as to the relation between the cells of the lymph and those of the effusion cannot be arrived at satisfactorily without repeated observations on the same animal.
Dr. Warthin examined many of the smears from these cases and frequently controlled the conclusions regarding the various types of cells. Dr. P. F. Morse assisted me frequently with the operative procedures and with the routine counting of the cells.