599 



mediana antebrachii. In four cases the Vv. cephalica et basilica were 

 alone present, the V. mediana cubiti, V. mediana antebrachii, and the 

 V. cephalica accessoria being all absent. In one case the brachial 

 portion of the V. cephalica was absent as previously mentioned, an 

 abnormality which obviously arises from the apparent natural tendency 

 of the superficial venous return to be switched over from the radial 

 to the ulnar side of the forearm. In 6 cases the anastomosis between 

 the Vv. cephalica et basilica by means of the Vv. mediana basilica and 

 the V. mediana cephalica was reduplicated (see Fig. 5). 



V. cephalica 

 V. basilica 



V. mediana cubiti 



V. cephal. accessoria 

 V. cephalica 

 V. mediana ante- 

 brachii 



V. cephalica 

 V. basilical] 



V. basilica 

 V. cephal. accessoria 

 V. cephalica 

 v. mediana ante- 

 brachii reduplicated 



Fig. 4. A reduplicated V. mediana 

 cubiti. 



Fig. 5. Reduplicated V. mediana 

 antebrachii. 



We have already given it as our opinion that the general ar- 

 rangement of the superficial veins of the superior extremity coincides 

 with that of the inferior extremity, and from these observations made 

 upon 300 living subjects we are further clearly of opinion that the 

 B.N.A. method of regarding the main venous return as by two longi- 

 tudinal truncs — the Vv. cephalica et basilica — coincides more closely 

 with the observed facts upon the adult, and with the known facts of 

 the embryological development of the upper limb veins than do the 

 older descriptions of M-shaped structures. As regards the embryology 

 McMuRRiCH (10) states: "The development of the limb veins of the 

 human embryo requires further investigation, but from a comparison 

 of what is known with what has been observed in rabbit embryos it 



