vi CIRCULATION OF BLOOD: ITS DISCOVEEY 165 



have some interest in debasing the merit of the Aretine, in order 

 to exalt that of Harvey. It is unfortunate that Ch. Richet, in his 

 Dictionnaire de physiologic now in course of publication, should 

 repeat Haller's mistake in regard to Cesalpinus, since it has been 

 contradicted by Ceradini, whose historical 

 studies he has evidently not consulted. 



A further and very convincing proof of 

 the circulation of the blood is the presence 

 of the valves, which occur abundantly along 

 the course of the veins, and are so contrived 

 that only the centripetal passage of the 

 blood is permitted, while the centrifugal is 

 impeded (Fig. 46). 



This evidence was not, however, adduced 

 by Cesalpinus, for which he has been criti- 

 cised by Sprengel, a medical historian. As 

 a matter of fact, although Cannanus of 

 Ferrara described certain valves of the 

 azygos vein in 1547, and showed that 

 their concavity was directed towards the 

 heart, Fabricius of Acquapendente, a few 

 years later, found and demonstrated to his 

 students analogous valves in all the veins 

 that contribute to the vena cavae. This 

 discovery was first published in De venarum 

 ostiolis in 1603, some ten years after the 

 publication of Cesalpinus' Questiones peri- 

 pateticae. 



On the other hand, it must be stated 

 that Fabricius, who first described the 

 valves of the entire venous system, did not 

 recognise their function, which is to check 

 the reflux of the blood in a centrifugal 



direction, and promote it in the centri- FJG 46 ._ Extenial iliac vein , 

 petal, by muscular force ; he assumed that 

 they were there to retard the current of 

 blood from the heart to the periphery of 

 the veins. Who, then, was the first to 

 establish the theory of the circulation upon 

 the function of the venous valves ? 



Ceradini deserves much credit for bring- 

 ing forward a series of important docu- 

 ments, which lead us to the logical conclusion that the first to 

 discover the function of the valves of the veins was the famous 

 Petrus Paulus Sarpi, theologian and canonist of the Venetian 

 Republic, the friend and pupil of Fabricius. It is a fact 

 that some contemporary authors ascribed the discovery of the 



slit down, and pinned 

 out to show the numerous 

 valves, in the shape of 

 swallows' nests, placed 

 singly or 'two to threa to- 

 gether, along its course. 

 (Calori.) , Tunica interna, 

 stripped oft' and turned over 

 at b c, valves ; d, tunica 

 externa ; e, orifices of branch 

 veins ; /, branching veins 

 cut through. 



