154 THE VOYAGE OF H.M.S. CHALLENGER. 



Of these, one (the external facial vein of Neugebauer^) passes backwards parallel with 

 the zygoma, and crosses the superficial surface of the digastric muscle to unite behind 

 the articulation of the lower jaw bone with the second branch. The second vein (the 

 occipital of Neugebauer) arises among the muscles of the neck, close to the occiput. It 

 passes downwards along the posterior border of the digastric muscle to unite with the 

 first branch. The large vein thus formed is joined by a thii-d branch, which carries ofi" 

 the blood from the deep muscles in the occipital region, after which it unites in the 

 basilar region with the deep veins of the head to form the commencement of the jugular 

 vein. 



The venous trunk formed by the union of the superficial veins unites immediately 

 behind the os quadi'atum with the deep branch (the internal facial of Neugebauer) of the 

 jugular vein. The deep branches of the two jugulars of opposite sides unite across the 

 middle line to form a venous arch, the convexity of which is directed forwards. This arch 

 rests against the palatal surface of the pterygoid muscles, and receives numerous small 

 branches from the base of the skull and from the palatal region. Each extremity of the 

 arch is prolonged backwards to unite with the common trunk formed by the superficial 

 veins of the head, and the two together form the commencement of the jugular vein. 

 From the point of origin the jugular vein passes backwards along the neck, in company with 

 the vagus nerve and subcutaneous cervical artery and tinder cover of the panniculus 

 carnosus muscle as far as the root of the neck. Here it enters the thorax, and crossing 

 the dorsal surface of the subclavian artery, unites with the subclavian to form the in- 

 nominate vein. In consequence of the transposition of the trachea and oesophagus to 

 the right of the middle line, the jugular vein of the right side is likewise displaced from 

 the front of the vertebral column, and lies altogether to its right side and in contact with 

 the posterior surface of the oesophagus. At the root of the neck, however, like these 

 structures, the jugular vein regains its normal relation to the cervical column. Each 

 jugular vein receives numerous branches from the trachea, oesophagus, and panniculus 

 carnosus muscle. One of larger size than the others arises among the extensor muscles 

 of the neck, and joins the jugular vein about the middle in length of the cer%'ical region. 



The Humeral Vein. 



The veins of the wing in the Penguins do not accompany, nor do they correspond 

 with, the arteries. They are for the most part of small size, and pass from both surfaces 

 of the wing towards its posterior margin, where they terminate in a single trunk of large 

 size. This, the basilic vein of Neugebauer (PL XL fig. 4), commences close to the tip 

 of the wing and passes upwards, lying in close relation to the posterior border of that 

 organ as high as the axilla. Having reached the axilla, it passes between the serratus 



^ Systema venosiim Avium, Nova Acta AcaJ. Nat. Cuiios, torn. xxi. 



