Nov. 6, 1879] 



NATURE 



it is clear that Aristotle, having failed to notice the 

 valves of the heart, did not distinguish the part of the 

 right ventricle from which the pulmonary artery arises 

 {R.t/) from the proper trunk of the artery on the one 

 hand, and from the right auricle (R.a) on the other. 

 Thus the root, as we may call it, of the pulmonary 

 artery and the right auricle, taken together, are spoken 

 of as the " part of the great vein w hich extends upwards ; " 

 and, as the vena azygos (Az) was one branch of this, 

 so the "vein to the lung" was another branch of it. 

 But the latter branch, being given off close to the con- 

 nection of the great vein with the ventricle, was also 

 counted as one of the twowopoi by which the "heart" (that 

 is to say the right ventricle, the left ventricle, and the left 

 auricle of our nomenclature) communicates with the lung. 



The only other difficulty that I observe, is connected 

 with (£). If Aristotle intended by this to affirm that the 

 middle cavity (left ventricle), like the other two, is directly 

 connected with the lung by a mpos, he would be in error. 

 But he has excluded this interpretation of his words by 

 (e), in which the number and relations of the canals, the 

 existence of which he admits, are distinctly defined. I can 

 only imagine then, that so far as this passage applies to 

 the left ventricle, it merely refers to the indirect commu- 

 nication of that cavity with the vessels of the lungs, 

 through the left auricle. 



On this evidence I submit that there is no escape from 

 the conclusion that, instead of having committed a gross 

 blunder, Aristotle has given a description of the heart 

 which so far as it goes, is remarkably accurate. He is in 

 error only in regard to the differences which he imagines 

 to exist between large and small hearts (A). 



Cuvier (who has been followed by other commentators) 

 ascribes another error to Aristotle : — 



" Aristote suppose que la trache'e-artere se prolonge 

 jusqu'au cceur, et semble croire, en consequence, que l'air y 

 pene'tre (/. c. p. 152,." 



Upon what foundation Cuvier rested the first of these 

 two assertions, I am at a loss to divine. As a matter of 

 fact, it will appear from the following excerpts that 

 Aristotle gives an account of the structure of the lungs 

 which is almost as good as that of the heart, and that it 

 contains nothing about any prolongation of the windpipe 

 to the heart. 



" Within the neck lie what is called the oesophagus (so 

 named on account of its length and its narrowness) and 

 the windpipe [aprqpla). The position of the windpipe in 

 all animals that have one, is in front of the cesophagus. 

 All animals which possess a lung have a windpipe. The 

 windpipe is of a cartilaginous nature and is exsanguine, 

 but is surrounded by many little veins .... 



" It goes downwards towards the middle of the lung 

 and then divides for each of the halves of the lung. In 

 all animals that possess one, the lung is divided into two 

 parts ; but, in those which bring forth their young alive, 

 the separation is not equally well marked, least of all in 

 man. 



"In oviparous animals, such as birds, and in quad- 

 rupeds which are oviparous, the one half of the lung is 

 widely separated from the other ; so that it appears as if 

 they had two lungs. And from being single the windpipe 

 becomes [divided into] two, which extend to each half of 

 the lung. It is fastened to the great vein and to what is 

 called the aorta. When the windpipe is blown up the air 

 passes into the hollow parts of the king. In these, are 

 Cartilaginous lubes (din<£i'<r€ir) whic'l unite at an angle; 



from the tubes passages (rp^/iara) traverse the whole of 

 the lung ; they are continually given off, the smaller from 

 the larger." (Book i., 16.) 



That Aristotle speaks of the lung as a single organ 

 divided into two halves and says that the division is least 

 marked in man, is puzzling at first, but becomes intelligible 

 if we reflect upon the close union of the bronchi, the pul- 

 monary vessels and the mediastinal walls of the pleurae in 

 mammals ; l and it is quite true that the lungs are much 

 more obviously distinct from one another in birds. 



Aubert and Wimmer translate the last paragraph of the 

 passage just cited as follows : — 



"Diese haben aber knorpelige Scheidewande, welche 

 unter spitzen Winkeln zusammentreten, und aus ihnen 

 fiihren (Jeffnungen durch die ganze Lunge, indem sie sich 

 in immer kleineren verzweigen." 



But I cannot think that by Siatpvo-fis and Tpt]p.ara, in this 

 passage, Aristotle meant either "partitions" or openings in 

 the ordinary sense of the latter word. For, in Book iii. 

 Cap. 3, in describing the distribution of the "vein which 

 goes to the lung" (the pulmonary artery), he says that it 



" Extends alongside each tube (<rvptyya) and each 

 passage (jprjita), the larger beside the larger, and the 

 smaller beside the smaller; so that no part [of the lung] 

 can be found from which a passage (rpr/pa) and a vein 

 are absent." 



Moreover, in Book i., 17, he says — 



" Canals (n-dpoi) from the heart pass to the lung and 

 divide in the same fashion as the windpipe does, closely 

 accompanying those from the windpipe through the 

 whole lung." 



And again in Book i., 17. — 



" It (the lung) is entirely spongy, and alongside of each 

 tube (ovpiyya) run canals (iropoi) from the great vein." 



On comparing the last three statements with the facts 

 of the case, it is plain that by trvpiyya, or tubes, Aristotle 

 means the bronchi and so many of their larger divisions 

 as obviously contain cartilages ; and that by Sicxpicrtis 

 Xo»8pa>S(ts he denotes the same things ; and, if this be soi 

 then the rpwara must be the smaller bronchial canals, in 

 which the cartilages disappear. 



This view of the structure of the lung is perfectly- 

 correct so far as it extends ; and, bearing it in mind, 

 we shall be in a position to understand what Aris- 

 totle thought about the passage of air from the lungs 

 into the heart. In every part of the lung, he says, in 

 effect, there is an air tube which is derived from the 

 trachea, and other tubes which are derived from the Trvpoi 

 which lead from the lung to the heart, supn't (c). Their 

 applied walls constitute the thin "synapses" (nfv avvatyip) 

 through which the air passes out of the air tubes into the 

 rnipoi, or blood vessels, by transudation or diffusion ; for 

 there is no community between the cavities of the air 

 tubes and cavities of the canals ; that is to say, no opening 

 from one into the other, suprd {d). 



On the words " koivos irdpos" Aubert and Wimmer 

 rem irk {I.e. p. 239), "Da A. die Ansicht hat die Lungen- 

 luft wiirde dem Herzen zugefiihrt, so postulirt er statt 

 vieler kleiner Verbindungen einen grossen Verbindungs. 

 gang zwischen Lunge und Herz." 



But does Aristotle make this assumption ? The only 

 evidence so far as I know in favour of the affirmative 

 answer to this question is the following passage : — 



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