326 BRUNER. [Vol. XVI. 



lungless form the pulmonary vein is wholly wanting ; the pul- 

 monary artery, on the other hand, has been preserved because 

 it supplies other parts than the lungs. In regard to the heart, 

 Bethge accepts the conclusions of Hopkins. 



Miss Woldt (33) found a pulmonary artery in Plethodon 

 erythronotus and P. cinereus, in which it supplies both oesoph- 

 agus and skin. Beyond the point of origin of the last 

 oesophageal branch no trace of the true pulmonary trunk could 

 be found. 



W. E. Ritter and Loye Miller (26) find in the toes of Autodax 

 lugubris great blood sinuses, which they consider an important 

 seat of respiration. "The toes have, in fact, assumed the func- 

 tion of external gills." 



The Heart of Salamanders with Lungs. 



The heart from which Fig. i, PI. XV, was drawn had been 

 injected immediately after death with 70^ alcohol, until all 

 blood was washed out. The large vessels were then ligatured 

 and the entire animal, with the heart, placed in 70^ alcohol. 

 After hardening, the heart was in excellent condition for study. 

 Figs. 3 and 4, PI. XV, represent sections of a heart injected 

 with blood only. The amount of distention is less here than 

 in Fig. I. 



The heart of Salamandra maculosa, which will be used as a 

 type in the following description, is composed of two different 

 sections — one for the reception and one for the expulsion of the 

 blood. The former includes the sinus venosus and two in- 

 completely separated auricles ; the latter includes the single 

 ventricle and the truncus arteriosus. The right auricle receives 

 blood from the general circulation ; the blood from the lungs 

 pours into the left auricle. Into the latter the pulmonary vein 

 enters directly, while the blood from the body passes first 

 into the sinus venosus, which lies on the dorsal side of the 

 heart and toward the left side. The sinus is formed by the 

 fusion of three large veins — the two venae cavae superiores, 

 which open into the sinus by separate mouths, and the vena 

 cava inferior, which enters the sinus at its posterior end. The 



