1895.] LTTNGS OF SNAKES, AMPHISB.13aDiE, ETC. 



693 



among jndmonate vertebrates in having tJie right lung completely or 

 partially suppressed. 



The "observations recorded in this paper are of course not 

 exhaustive, but I think the types examined make up a good 

 representative set ; and though it is of coiu-se not safe from a 

 knowledge of the anatomy of nine animals to prophesy as to that 

 of a tenth though apparently nearly related, still I think the 

 probability is that if we open a specimen of any species of 

 Amphisbffiuid we shall find the left lung well developed and the 

 right lung smaller, rudimentary, or absent, and that in any other 

 animal, if one lung is markedly smaller, rudimentary, or absent, it 

 will be the left lung. 



In itself the suppression of one lung rather than the other does 

 not perhaps appear to be a characteristic of great significance ; 

 and if, as has been stated, it were a fact that some Snakes had the 

 right lung rudimentary and some the left, the case would be 

 different. If, however, as my observations so far as they go 

 indicate, the suppression of the right lung is really confined to one 

 family of animals, which are peculiar and interesting in other 

 ways, it is sui-ely a point worth noting, both for its own sake and 

 because it may probably be indicative of some less superficial 

 peculiarity in the plan of organization of these animals, t; 



I may perhaps be able to follow up the matter some other time 

 when i more fully understand the significance of certain other 

 peculiarities of these animals. The main object of the present 

 paper is to state the facts observed. 



If any exceptions to the generalization above stated should be 

 discovered \ I should be much interested to hear of them. _ Such 

 exceptions, if they exist, would not improbably be suggestive in 

 one way or another. Let no one, however, after reading this 

 paper speak of a nidimentary left lung in an Amphisbsenid or a 

 rudimentary right lung in a Snake or any animal other than an 

 Amphisbsenid until he has first carefully re-examined his specimen 

 in the light of what follows. 



For permission to examine a number of species of which I do 

 not myself possess specimens my best thanks are due to my former 

 teacher Prof. Gr. B. Howes, and secondly to Mr. G. A. Bou- 

 lenger, F.E.S. The latter has also very kindly named my 

 specimens in accordance with his latest edition of the British 

 Museum Catalogues of Snakes and Lizards. 



II. A Eeview or peeviotjs Statements. 



At the end of this paper will be found a list of the works which, 

 so far as my knowledge goes, contain the most noteworthy 



1 For a discussion of the clescription and figure of the lungs of Chirotes by 

 Cuvier and Flourens respectively, see below, pp. 694, 702. 



I hope that anyone who has an opportunity of dissecting either Chirotes or 

 any snake-like Lizards not mentioned in my lists will make an outline sketch 

 of the heart, lungs, and liver, in situ, as seen from the ventral side, so as to 

 show the relative size of the two lungs. 



