1 40 MR. F. E. BEDDARD ON THE ANATOMY [Mar. 3, 



of this seam running down the lungs for some distance after the 

 intrapuhnonary bronchus has ceased as a series of cartilaginous 

 bars, C'o7riUiis cookii has at most a small representative of this 

 seam, which appears to be in some specimens actually absent. 

 There is thus in any case a difference between the two species. 

 It is necessary, however, to describe in greater detail the con- 

 dition of the lungs in the specimens which I have dissected. 

 In specimen A there was no seam at all ; in B and D there was 

 a distinct seam ; in E, F, and Gr, I could find no seam. Of C, 

 I have no observation upon the point. It would appear there- 

 fore that in Corallus cookii the seam is at least beginning to 

 disappear, while there is no evidence that that is the case with 

 G. madagascariensis, though the latter data being based upon one 

 specimen are obviously not so secure. 



The A^ariations in the lungs of Corcdlus cookii do not, however, 

 stop with the presence or absence of the longitudinal seam. The 

 accompanying figures (text-figs. 21 & 22, p. 139) illustrate the 

 anterior end of the lung in two individuals of Corallus cookii, and I 

 have had drawn for comparison with them a corresponding portion 

 of the lung of Python spilotes, in which snake there is a very con- 

 spicuovis seam continuing the bronchvis down the lung (text-fig. 23). 

 There is, however, in Pytho7i no vestige of a tracheal lung and the 

 intrapulmonary bronchus is quite short. The lungs of Corallus 

 cookii figured are from the specimens D and E ; one shows a seam 

 and the other does not. Although in the lung which was removed 

 from specimen E there was certainly not the faintest trace of a 

 seam to be noted when the lung was examined in a fresh condition, 

 appearances indicative of such a seam were to be seen in that 

 lung after it had lain for some little time in a solution of formol. 

 It occurred to me therefore, on a re-examination of the lung after 

 it had been thus prepared, that some error must have crept into 

 my notes. The matter is of obvious systematic importance, as 

 will be pointed out later on in connection with the variation of 

 another organ (the gall-bladder), and so a careful study of the 

 lung was made, I fovmd that the appearance of a seam in this 

 lung was in trvith only an appearance ; in fact, a contraction 

 produced by the formol had manifested itself along the line of 

 junction of the two lungs, and here it was that the seam appeared. 

 Bvit on pulling apart the sui'faces of the lung the " seam " was 

 observed to disappear at once and to be therefore not a permanent 

 structure, but merely a wrinkle produced by the contraction due 

 to the formol. On the other hand, no amou.nt of pulling apart 

 would obliterate the real seam of the second lung figured, that 

 of specimen D, Here, therefore, was a real seam, a permanent 

 structure. It is possible, however, that these appearances, due 

 to contraction, may be an indication of how the seam really arose 

 in the first place. A contraction along the line of fusion of the 

 right and left lungs might possibly become permanent in the 

 course of generations. With regard to the seam, it is noteworthy 

 and qviite apparent in the figure that it did not begin immediately 



