462 ANATOMY OF VERTEBRATES. 



by a large plexus, filling up the haemal canal ; they present also 

 a plexiform character at the axilhe and base of the neck, about 

 the jugular veins ; but the vasiform character is generally better 

 mai"ked in the lymphatics of the Crocodile than in lower Reptiles, 

 and the valves occur more frequently. 



The lymph-corpuscles are very few, and rarely visible in the 

 lymphatics of the tail of the Tadpole, but were numerous in the 

 lymphatic canals near the liver in Salamandra. By carefully 

 puncturing the large subcutaneous lymph-reservoirs of the Frog, 

 at the upper part of the thigh, the pure fluid may be obtained 

 from the living animal : but analysis of lymph has chiefly been 

 performed on the larger quantities discharged from artificial 

 fistula? of the thoracic duct in the Horse and Cow, and its results 

 will be given in connection with the Mammalian class. 



