170 PHYSIOLOGY CHAP. 



convince the unbelieving, and he gives four figures of ligatured 

 arms (one of which is an exact reproduction of the " Figura L, 

 Tabulae II. brachii vivi ad sanguinis missionem ligati " from the 

 treatise of his master Fabricius, De venarum ostiolis) which 

 demonstrate the varicose and congested veins at points correspond- 

 ing with the position of the valves (Fig. 47). The valves are not 

 intended to hinder the accumulation of blood in the lower parts of 

 the body, for they are found also in the jugular veins, which run 

 down from above, in the renal and mesenteric veins, etc. These 

 impede the flow of blood from the greater to the lesser veins, to 

 prevent their becoming lacerated and varicose ; they show that 

 the blood in the veins flows, not from the centre to the extremities, 

 but from the extremities to the centre. Injections from the greater 

 to the lesser veins are often arrested by the resistance of the 

 valves, while no difficulty arises in injecting from the small to the 

 great veins. 



If the blood in a vein is compressed with the finger in the 

 ligatured arm, it will be seen that the blood which has passed 

 beyond the swelling (formed by a valve) cannot regurgitate, and 

 the portion of the vein between the swelling and the finger seems 

 to be obliterated. The function of the venous valves is therefore 

 the same as that of the semilunar valves of the aorta and the 

 vena arteriosa (pulmonary artery), which close the ostiuin and 

 hinder the blood from flowing backward. 



VI. It might be thought that the Theory of the Circulation of 

 the Blood as demonstrated by Cesalpinus, and completed by 

 Harvey, would have won its recognition in science, and have been 

 universally accepted and adopted. 



Opponents, however, were not wanting, among the most 

 important and stiff-necked being Jean Eiolan, the famous Parisian 

 anatomist, and Kaspar Hoffmann, a celebrated German scientist of 

 the day, who, like Harvey, had been a disciple of Fabricius of 

 Acquapendente. They recognised that the new doctrine under- 

 mined the foundations of the medical science of their day, and all 

 means seemed to them lawful to avert what they held to be a 

 serious danger. Needless to say, this opposition (although it 

 showed up certain defects and fallacies in the work of Harvey) 

 only succeeded in spreading the new doctrine more widely, and 

 making it better appreciated. Ceradini's observation is very apt, 

 to the effect that " Harvey owed his fame to the Parisian anatomist 

 who, after the death of Fabricius, was reckoned the first authority 

 in Europe ; and the error of the English partisans lies in the 

 parallel they established between the impression produced on 

 the scientific world of his day by his writings and those of 

 Cesalpinus. Had Cesalpinus in his lifetime encountered a Eiolan, 

 to accuse him of plagiarism, of absurdity, and of heresy ; had he 

 not for more than thirty years developed peacefully from his 



