LUNGS OF REPTILES. 52,5 



of Bipes lepidopus. In Pseudopus Pallasil the lungs are of nearly 

 equal length. 



In most Laccrtian Reptiles the lungs are equal, are broader 

 in proportion to their length, and the short bronchus terminates 

 abruptly in the single pulmonary cavity. The parietes are honej'- 

 combed and 'vascular, but in a less degree as they extend from the 

 heart : in Geckos and Agamas the alveoli are deepest on the 

 mesial side of the lungs. In the Iguana the pulmonary cavity is 

 divided by a few deep partitions into primary lodges, the parietes 

 of which are honeycombed by secondary and tertiary cells.' In 

 a Monitor {Jlegmia ocellata) the bronchus is continued some way 

 along the interior of the lung.^ The lungs of the Chameleon are 

 remarkable for their great extent, for the delicacy of their 

 parietes, and tlic number of c;vcal processes continued from their 

 anterior and inferior margins. Each lung is partially divided 

 longitudinally at its fore ]iart into two cavities, which have their 

 vascular surface increased by subdivision into cellular alveoli ; 

 the posterior appendiculated part of the lung is of a simpler 

 and loss vascular structure, and may serve as a reservoir of 

 air. Marginal ca3cal productions of the pulmonary bag exist also 

 in the Geckos (e. g. Ptijodacfijlus Jindjriatiis) and in Pohjchrus 

 marmoratus. In Geckos and Scinks the trachea terminates in 

 the lungs without dividing into bronchi. 



In the Chelonia the lungs present a further stage of complica- 

 tion, and are adherent to the surrounding parts. In those of 

 Chehjdra serpentina, e.g. the general cavity of each lung is divided 

 into eight compartments, the walls of which are honeycombed 

 and vascular, especially at their fore part. The bronchial tube 

 extends to the hindmost compartment of the lung,'^ communi- 

 cating l^y special orifices with the anterior ones, and sending 

 continuations of its fibrous structure along the free border of 

 the septa. 



In the Sea-Turtles ( Chelone) the lungs extend over the back 

 part of the abdomen to the pelvis, and must act as an air-bladder 

 during their swimming : 4 the bronchial tubes are continued, 

 gradually decreasing, to near the end of the lungs, and retaining 

 cartilaginous rings or half-rings along three-fourths of their 

 course. They communicate with numerous primary divisions of 

 the pulmonary cavity, each of which is divided into cells, which 

 are subdivided to the third or fourth degree, with proportionate 

 extension of the vascular respiratory surface. The ultimate cells 



' XX. ib. p. 96. ■ cccxxi. p. 525. 



' Ib. p. 96, prep. no. 1109 A. ' Ibid. p. 96, prep. no. 1110. 



