BOOK XI. Lxxxvin. 218-xc. 221 



Where there are sinews, the inner ones contract the 

 limbs and the ones on the surface reverse the move- 

 ment. 



LXXXIX. Between the sinews lie the arteries, Theartene» 

 which are the passages for the breath, and on 

 these float the veins, which are the channels for 

 the blood. The pulse of the arteries being parti- 

 cuiarly evident at the extremity of the hmbs is 

 usually a sign of diseases ; with remarkable scientific 

 skill it has been reduced by that high priest of 

 medicine, Herophilus, to definite rhythms and 

 metrical rules throughout the periods of life — steady 

 or hurried or slow. This sign " has been neglected 

 because of its excessive subtlety, but yet really it " 

 supphes " a rule for the guidance of Hfe by observation 

 of the pulse-beat, rapid or languid. The arteries 

 have no sensation, for they even are without blood, 

 nor do they all contain the breath of Ufe ; and when 

 they are cut only the part of the body concerned is 

 paralysed. Birds have not got either veins or 

 arteries, nor yet have snakes, tortoises and Uzards, 

 and they have only a very small amount of blood. 



The veins spread underneath the whole skin, finally 

 ending in very thin threads, and they narrow down 

 into such an extremely minute size that the blood 

 cannot pass through them nor can anything else but 

 the moisture passing out from the blood in innumei'- 

 able small drops which is called sweat. The junction 

 and meeting point of the veins is at the navel. 



XC. Creatures wliose blood is copious and thick Thebiood. 

 are hot-tempered. The blood of males is darker than 

 that of females, and that of youth than that of old 

 age ; and it is thicker in the lower part of the body. 

 The blood also contains a large proportion of vitality, 



571 



