Studies upon the Influence of Tension in the Degeneration of Elastic Fibres of Buried Aortæ

The experiments described in this paper were carried out with the object of studying the power of resistance possessed by elastic tissue to degenerative changes, the order of such changes as do occur when this resistance is overcome, and the effect of continuously applied tension upon these fibres. Space does not permit of more than a brief review of the investigations already made by pathologists upon this tissue under various abnormal conditions. For more detail the reader is referred to a very concise paper by Jores, in Lubarsch and Ostertag's Ergebnisse der allgemeinen Pathologic (i9o2, Jahrgang VIII, p. 590). Disappearance of Elastic Fibres.-Under various pathological conditions, organs, which show in health a large quantity of elastic tissue, exhibit a very marked decrease, if not total absence, of these fibres. The cause of this disappearance is much disputed. Du Mesnil de Rochemont considers that degeneration of elastic fibres is due to chemical action. He comes to this conclusion from observations made upon tuberculous material. He believes that the breaking down and disappearance of the elastic tissue is the result of free toxins which are the products of the bacillus of tuberculosis. In experimental pulmonary tuberculosis in animals produced by injecting cultures of the bacillus into the vascular system, Wechsberg noted a disappearance of the elastic fibres of the lung; this condition was recognizable within six hours and was very marked at the end of two days. He attributed it to the action of toxins of the microorganism. In sections of lupoid material, du Mesnil de Rochemont found a narrow marginal zone, about a line in width, which was free from 388