VOL. XXIII.] PHILOSOPHICAL TRANSACTIONS. 681 



position : some of these tables being finished by the direction and public appro- 

 bation of the professor and several other physicians and anatomists, present at 

 those lectures and operations ; and understanding that Leoncenae was about to 

 dispose of his tables, I desired the late Dr. Geo. Rogers, then consul at Padua, 

 for the students of our nation in that university, to purchase and procure them 

 for nie ; which he did for 1 50 scudi ; with condition, that he should add a table 

 more, viz. that of the liver, the gastric nerves, and other vessels, to complete 

 the fourth, &c." J. Evelyn. 



These figures are accurately drawn after the original schemes ; and it is some 

 satisfaction to me, that I find the arteries here so agreeable to a figure which I 

 drew and published not long since, from the arteries of a foetus injected with 

 wax. But this figure of the veins differs so much from any extant, as to incline 

 one to suspect all of the subject hitherto published are fictitious, not excepting 

 even those of Vesalius. But first of the arteries. 



That the arteries are the vessels which convey blood from the heart to all 

 parts of the body, is well known ; and it is the common practice of nature, in 

 distributing these vessels, to supply the parts with blood from the next ad- 

 jacent trunk, till their ascending and descending trunks become conical, as 

 well as their collateral branches : not that all the trunks and ramifications of 

 arteries are uniform, and become conical in the same manner ; nor do they all 

 pass directly to the parts to which they convey blood ; nor do all the parts re- 

 ceive arteries from their neighbouring trunks. 



The trunks of the carotid, vertebral, and splenic arteries in adults, are not 

 only contorted in their progress, but the diameters of their bores are variously- 

 dilated in divers parts, especially where they are contorted ; but as these dilata- 

 tions of their trunks are caused by the resistance the blood meets with at those 

 angles of inflection, so those enlargements of them afterwards contribute to re- 

 tard the protrusion of the blood to the extremities of those arteries : hence it is, 

 that as the arteries of the fcEtus are not contorted in such acute angles as in 

 adults, so their trunks are more conical, and not here and there dilated in divers 

 parts of them, as in the latter. The trunk of the splenic artery has a straight 

 progress in the foetus and infants ; but in the adult I have hitherto constantly 

 found it very contorted, as expressed in the figures. 



The peculiar contrivance of the spermatic arteries of quadrupeds, as well as 

 men, shows a constant design in nature to take off that velocity with which the 

 blood would otherwise pass through the glands of the testes : it seems to be for 

 this end that the testes of most animals, especially men and quadrupeds, hang 

 out of the cavities of the abdomen, that the canals of their blood vessels may be 

 lengthened ; for the spermatic arteries, contrary to all others, arise from their 



vol.. IV. 4 S 



