FROZEN SECTIONS OF THE THORAX. 



341 



Pig. 100. — Frozen Teansection of the Thorax, Cephalic Aspect ; x 1.5. 



mediastinale to become continuoas with the parietal pleura. The ental lamina is reflected 

 to form the proper serous covering of the heart. At the dorsal points of junction of the 

 two laminae are the phrenic nerves. 



The sternal arteries and mins appear dorso-laterad of the mesosterneher. The veins 

 lie mesad of the arteries (§ 921). 



§ 911. Nerves, etc. — The sympathic trunks {W. sympathkus) appear just ventrad of 

 the heads of the ribs in Fig. 99, and in corresponding places in Fig. 100. 



