ABSORBENTS OF REPTILES. 459 



form of a ( thoracic duct ' in the Newt ; it proceeds along the aorta 

 in both, communicating with lymphatic canals near the liver, and 

 dividing anteriorly, to accompany the right and left aortic arches, 

 and to receive the lymphatic conduits from the head and fore-limbs, 

 before terminating in the subclavian veins. Some of the vessels, 

 both arteries and veins, of the trunk have a similar lymphatic 

 sheath, but the principal conduits of the lymph, in the Batrachia, 

 have the form of irregular sinuses or lacunae, of great capacity 

 between the skin and flesh, and of smaller size in the inter- 

 muscular spaces of the limbs. 1 Air or liquid introduced into 

 these lymph-receptacles finds its way into the veins by the above, 

 and perhaps other, communications. The lymphatics of the 

 hind-part of the body and limbs communicate with a pair of 

 subcutaneous receptacles, with contractile walls, behind each 

 femoral joint ; there is a similar pair in front of the scapulas. 2 

 These receptacles have a subrhythmical action, not synchronous 

 with one another, or with the pulsations of the heart, or with 

 any of the movements of respiration, which in Batrachia are 

 degiutitioual chiefly. The muscular fibres of these ( lymph- 

 hearts ' are of the striped kind. 3 The cervical pair transmit 

 their lymph into the jugular veins, and distend them at each 

 systole. The pelvic lymph-hearts have been seen to pulsate 

 sixty times in the minute in a frog. 4 In the large Ceratoplirys 

 cornuta two pairs of ischiadic lymph-hearts have been found. 5 



In the Tortoise the pelvic lymph-hearts are two, of a more 

 circumscribed rounded form, situated on each side of the bodies 

 of the vertebras, between the femoral joints and the hind-border 

 of the carapace ; the valves at the inlets and outlets of the 

 lymph conduits, impressing the course of motion of the fluid, 

 are here readily seen. 6 In Lizards and Crocodiles the pelvic 

 lymph-hearts are situated near or upon the diapophyses of the 

 first caudal vertebra. In Pseudopus Pallasii they lie between 

 the muscles upon the sacral diapophyses, receiving the lymph 

 each by a single conduit from the great abdominal sinus, and 

 transmitting it to the umbilical veins ; they pulsate about fifty 

 times in the minute. 7 In true Serpents (Python, e. g.) the 

 lymph-hearts are elongate, and situated behind the last pair of 

 ribs and upon the rib-like diapophyses of the anterior caudal 

 vertebras ; they receive the lymph by three orifices at one end, 

 and transmit it by two opposite orifices, to conduits com- 



1 CCLVII. p. 28. ~ CCLV. p. 89. 3 CCLVIII. p. 58. 



4 LXXIV. 5 Ib. 6 CCLV. pi. 1. 7 CCLIX. p. 25, pi. 3. 



