Abstract
Summary
1. Blood coagulation times and tissue mast cell counts were determined on summer and winter bats and upon their exposure to 5°C and 23°C; respectively. 2. In nature the blood clotting time of the active summer bat is short, while that of the dormant winter bat is prolonged. Exposure of the summer bat to 5°C and the winter bat to 23°C in the laboratory results in a lengthening and a shortening of the clotting, respectively. The number of tissue mast cells in the duodenum appear to increase in the former case and decrease in the latter instance. 3. The above changes are interpreted as indicating the presence of a mechanism which prevents thrombus formation under the conditions of slow blood flow during dormancy and which allows for rapid clotting when the bat is active. The mast cell changes suggest that the alterations in clotting time are determined at least in part by alterations in the availability of heparin to the circulation.
Get full access to this article
View all access options for this article.