I. Contributions to the normal and pathological anatomy of the lymphatic system of the lungs

Abstract

I propose to give in the following pages a summary of an investigation of the lymphatic system of the lungs, in the normal condition as well as in chronic secondary inflammation, undertaken in connexion with the pathological inquiries of Dr. Burdon Sanderson, for the Medical Department of the Privy Council. The research will be published at length during the course of the next year, in continuation of my work ʻOn the Anatomy of the Lymphatic System,ʼ of which the first part, “Serous Membranes,” has recently appeared. The present communication is made with the approval of the medical officer of the Privy Council, Mr. Simon. A. Normal conditions. ( a ) The endothelium of the surface of the lungs consists, in the normal condition, of polyhedral cells (not flattened as commonly described) arranged in a single layer. This is well seen in guineapigs, less distinctly in rabbits, rats, dogs, and cats. If the lung is not distended, the endothelium of the surface very much resembles an epithelium, the cells being polyhedral, or in the form of short columns; they are markedly granular, and have distinct nuclei. Even in the moderately distended lung, the endothelium of the pleura pulmonum is by no means of the same morphological character as that on the costal pleura. Between the endothelium of the one and that of the other organ there exists the same difference as between that of the ovary and that of the peritoneum—the one consisting of polyhedral, or shortly columnar, granular cells with very marked nuclei, the other of very flattened, almost hyaline, endothelial plates.