01s THE CERVICAL VEINS AND LYMPHATICS IN FOUR 

 HUMAN EMBRYOS, 



With ais' Ixteepeetatiojst of Anomalies of the Subclavian and 

 Jugular Veins in the Adult. 



FREDERIC T. LEWIS. 

 Fi-om the Department of Anatomy, Harvard Medical School. 



In order to explain an anomaly of the subclavian vein occurring 

 in a man 68 years old, reconstructions of the cervical veins and 

 lymphatics in four human embryos were made, with the following 

 results. In an embryo having a maximum measurement of 10 mm., 

 the right arm is drained by a primitive ulnar vein which unites with 

 a thoraco-epigastric vein to form the dorsal subclavian vein. These 

 vessels are sho^^Ti in Fig. 1. The primitive ulnar vein is seen to 

 receive a branch near the elbow, and distally it has many smaller 

 tributaries which have been omitted from the drawing. There are 

 no veins larger than capillaries along the radial border of the arm. 



The thoraco-epigastric vein, which is found in the lateral body 

 wall, is represented in fishes and in all the higher classes of verte- 

 brates. Unfortunately it has been given a great variety of names. 

 In the rabbit it is called the external mammary vein (Krause,'^ 

 Lewis^) and this name has been applied to it in man (Poirier^). In 

 man it has been called, in part at least, the long, lateral, or inferior 

 thoracic vein, but the term thoraco-epigastric is preferable to any of 

 these. 



The primitive ulnar and thoraco-epigastric veins unite to form a 

 subclavian vein which passes dorsal to the brachial plexus to enter the 



'Ki-ause, W. Die Anatomie des Kanincheus. Leipzig, 1868. 

 -Lewis, F. T. The development of tbe lympliatic system in rabbits. Amer. 

 Joiirn. of Anat, 1905, Vol. 5, pp. 95-111. 

 ^Poirier, P. Trait§ d'anatomie humaine. Paris, 1896. Vol. 2, p. 911. 



The American' Jocexal of Anatomy. — Vol. IX, No. 1. 



