1903.] 



AXATOMY OF THE JAPANESE SALAMANDER. 



311 



" short circuiting " of the blood-stream *. On the oj)posite side 

 of the carotid, just where this transverse connection occurs, a 

 small artery is given off which also runs forward. It is not shown 

 by Osawa. The lingual branch just referred to runs forward and 

 ends in two slender branches ; before this termination it gives off 

 a backwardly-running branch, which lies parallel to itself, and then, 

 bending to the middle line of the body, runs parallel to the trunk 

 of the carotid at its origin. It gives off an equally strong branch 

 running forwards. The deep carotid artery (text-fig. 32, p. 309) 

 arises from the carotid arch just before the junction of the former 

 with the common aortic trunk. Close to the lower bend of the 

 carotid, just where it gives off the lingual artery, is a small reddish 

 body, served by an artery from the carotid (not shown in text- 

 fig. 33), which I take to be a part of the thymus. Another body 

 of a similar form lies further back in the neck. 



Text-fig. 33. 



Heart and Arterial Trunks of Megalohatraclms from the side. 



1-4, vascular arches ; A, anteriorly running branch of carotid ; 

 Br, branchial twigs ; P, main branch of pulmonary. 



The second arch is partly protected by a branchial muscle, and 

 a smaller muscle arches over the third branchial trunk. The 

 second arch gives off a small branch running upwards, which 

 appears to me to correspond with the small branch supplying 

 the thymus in the case of the carotid. This is not figured by 

 Osawa, who does figure such a twig arising from a connecting 

 branch between this and the next arch. 



The third vascular arch again gives off a similar branch ; but 

 this joins a twig from the pulmonary, which will be described 

 immediately. 



The fourth or pulmonary artery runs a course which is by no 

 means so simple as is figured by Hyrtl or Osawa. It bends back, 

 and folloAvs almost exactly the edge of the pericardium. The 



* I found this only upon one side of the body. 



