614 LYMPHATIC SYSTEM. 



tubuli, the liver and gall-bladder, the testes and ovaria, and 

 even the minute laminae of the gills where their larger 

 branches follow the course of the branchial arteries along the 

 concavities of the arches. 



The lymphatic vessels have been shown by the numerous 

 careful injections of Panizza, Muller, and others, to be no 

 less extensively distributed through every part of the body 

 in the naked batrachian animals or amphibia, than in the 

 fishes, and they are maintained by Panizza to be here, and 

 in all higher classes, a distinct, isolated system of vessels, 

 from their origin to their termination, by great trunks, in the 

 venous system. He has represented, in his splendid plates, 

 taken from his own preparations, the crowded distribution 

 of these plexiform and beaded vessels, over all the subcuta- 

 neous parts of the body, and forming compact layers around 

 the interior viscera, especially on the spleen, in frogs and 

 salamanders among the amphibia, as well as in serpents, 

 lizards, crocodiles, and tortoises, among the true reptiles ; he 

 considers the skin as altogether different in properties from 

 mucous membranes, and that the batrachia are incapable of 

 respiring through their soft and naked skin. Between the 

 skin and the subjacent muscles of the higher amphibia there 

 are large lymph spaces which appear to communicate freely 

 with the lymphatic vessels, they are readily filled by inflation 

 of the lymphatic hearts, and they usually contain a consider- 

 able quantity of lymph which escapes on cutting the skin. 

 The great receptacle or thoracic duct of the frog, forms a 

 wide continuous sac extending along the whole dorsal region 

 of the cavity of the trunk, above the abdominal viscera ; the 

 large receptacle of the salamander, in extending forwards, 

 divides and reunites, and again bifurcates before entering the 

 two subclavian veins. 



Muller at Berlin and Panizza at Pavia discovered, about 

 the same time, two symmetrical pairs of pulsating muscular 

 cavities, on the large brachial and crural lymphatics, in 

 the regions of the neck and pelvis in the naked amphibia, 

 and similar pulsating sacs have also been detected on the 

 lymphatics of some reptiles and birds. The pulsations of 

 these lymphatic sacs are not synchronous with those of the 

 heart, nor even with each other ; and they continue after the 

 heart has been dissected from the body, or the body cut to 



