262 Dissection of two doubtful reptiles . 



Jy, less adapted to the purpose of aerating the blood. As, 

 however, blood and air will act reciprocally upon each other 

 through bladder, this circumstance will not of necessity pre- 

 vent these projections from performing the office of gills. 



The internal structure of the animal was found so precisely 

 to resemble that of the Proteus, that a detailed account of it 

 is deemed superfluous. I may remark, however, that the 

 mouth is devoid of teeth. 



The Edinburgh Philosophical Journal,Vol.V. contains some 

 remarks on the Siren lacertina and Proteus anguinus. The 

 author of these remarks admits the former of these animals to 

 be amphibious ; the latter, he insists, is exclusively aquatic. 

 The former he considers a larva, the latter he concedes, of 

 course, to be perfect. That the Siren, however, is no larva, 

 has been proved in this city, where one has been kept alive 

 for two or three years until it died, without its showing any 

 disposition to change its form. 



The reasons assigned for supposing the Proteus to be a fish, 

 as far as respiration is concerned, are as follows : First, the 

 want of a distinct pulmonary circulation. Secondly, their 

 being no apparatus for filling and emptying, what Cuvier and 

 myself consider as lungs, but what the authors in question 

 contend, are nothing more than the ordinary air-bladders of 

 fish. Thirdly, the length and intricacy of the passage by 

 which these lungs or air-bags, communicate with the atmos- 

 phere. Lastly, the inability, as they say, under which the 

 Proteus labours, of existing any where except in the water. 

 This last remark, if well founded, is doubtless conclusive; 

 but the other arguments, although ingenious and not without 

 their weight, are not insuperable. 



It is admitted that blood* is sent to the organs in question; 



* Note. According to Cuvier, the whole of the blood passes through 

 the pulmonary system, an arrangement altogether incompatible with the 

 idea of mere nutrition. 



