From the left ventricle of the heart, alongside its auricle, two arteries are given off. One of them, which is only furnished with one tunic (as in the case of a vein) and which is called the _arteria venalis_ (pulmonary vein), carries to the lungs the blood which they require for their nourishment, and breaks up into many branches after entering these structures; the other artery is provided with two tunics and is called _the grand artery_ (the aorta). From the latter vessel are given off the numberless arteries which are distributed throughout the entire body--vessels which transport to every organ and structure both the blood which they need for their nourishment and the spirit required for their revivification. When this spirit passes into the ventricles of the brain it is subjected to a new species of digestion, which converts it into the _spirit of the soul_. Similarly, when it enters the liver it becomes _a nutritive spirit_; when it enters the testicles, _a generative spirit_, and so on through all the different organs. CHAPTER XXIV DURING THE LATTER HALF OF THE MIDDLE AGES SURGERY ASSUMES THE MOST PROMINENT PLACE IN THE ADVANCE OF MEDICAL SCIENCE During the first half of the fourteenth century, as has been shown in the preceding chapter, Henri de Mondeville was largely successful in rendering Paris the most prominent centre of medical activity in France, if not in Western Europe generally. His life, however, was short, and his position as one of the leading surgeons of the French Army subjected him to many and prolonged interruptions, for which reasons he was not able to complete his excellent treatise on surgery. No physician of the same intellectual capacity and of equally strong character appears to have been living in Paris at the time of De Mondeville’s death, and consequently the importance of that city as a centre of medical education diminished rapidly after that event. On the other hand, the Medical School at Montpellier in the southern part of France began at about this period, under the influence of Arnold of Villanova (probably a small town in Catalonia, Spain, in the diocese of Valencia), to acquire importance.