In four memoirs on the dynamics of the circulatory system  resulting from 337 experiments recorded in this workSpallanzani studied the role of the circulation in every stage from embryo to adult, and it was through his researches on the vascular system in the umbilical cords of embryo chicks that he first established the existence of arteriovenous anastomoses in warm-blooded animals. He also investigated the effects on the circulatory system of growth, gravity, and the consequences of wounds, as well as the changes affected in the failing circulation of dying animals. He determined that the arterial pulse was causedb y lateral pressure upon the arterial wall from cardiac impulsions conveyed by the blood column.

Digital facsimile of the 1773 edition from Biodiversity Heritage Library at this link.

Translated into English as Experiments upon the circulation of the blood, throughout the vascular system: On languid circulation: On  the motion of the blood, independent of the action of the heart: And on the pulsations of the arteries. With notes, and a sketch of the literary life of the author. By J. Tourdes. Translated into English, and illustrated with additional notes by R. Hall. London, 1801. Digital facsimile of the English translation from Google Books at this link.