452 DR. C. F. SONNTAG OX THE 



external anterior thoi'acic nerves have no connection with the 

 outer cord. 



The muscido-cutaneous nerve gives off branches to the coraco- 

 bracliialis, biceps, and brachialis anticus, and the latter is of 

 considerable length. 



The circumflex nerve gives off a large nerve to the tei'es minor 

 (T.M), but no ganglion is present on it as in Man. The 

 remainder runs round the humerus, and divides into two parts 

 which end in the deltoid (D.B). 



The musculo-sinral nerve gives off upper and lower branches to 

 the triceps (U.T.B and L.T.B), and a long branch to the dorso- 

 epitrochlearis (D.E.M). It turns sharply round the humerus, and 

 divides into radial and posterior interosseous nerves at a point an 

 inch proximal to the elbow joint. 



The Nerve of Bell (long thoracic) arises from the sixth nerve, 

 and receives a fine communicating branch fi'om the fifth. 



The Lu'inho-sacrcd Plexus (text-fig. 24) is a long seiies of 

 anastomoses between spinal nerves, and the branches are long and 

 comparatively unbranched till they leave the abdomen and pelvis. 

 The arrangements differ from those in Man, for there are more 

 spinal nerves, and the muscles differ. 



The plexus communicates above with the last dorsal nerve. 



The first lumbar nerve communicates with the last dorsal and 

 second lumbar nerves, and becomes the ilio-hypogastric nerve. 

 The second lumbar nerve communicates with the first and third 

 and becomes the inguinal. The second, third, and fourth enter 

 into the lateral cutaneous nerve of the thigh. The third and 

 fourth form the obturator nerve. The third, fourth, and fifth 

 form the anterior crural. The fifth and sixth unite to form the 

 lumbo-sacral cord which passes to the sacral plexus. The sacral 

 and coccygeal nerves give mesial and lateral branches. The 

 mesial ones include muscular nerves to levator ani, coccygeus, and 

 pyriformis. The lateral ones include both sciatics, both gluteals, 

 and the nerve to quadratus femoris. 



Summary anb Conclusions. 



The following facts are described for the first time in the 

 Primates except Man : — 



1. The delto-pectoral triangle and contents. 



2. The costo-coracoid ligament replaced by a costo-humeral. 



3. The double nei*ve supply of the Axelbogen. 



4. Contluence of both ejaculatory ducts. 



5. Absence of the sinus pocularis. 



6. The right ventricle forining the cardiac apex. 



7. The Annulus of Yieussens encircling the subclavian and 

 vertebral artei-ies. 



8. The absence of any semilunar ganglia in the solar plexus. 



9. Analysis of the lumbar plexus. 

 10. Absence of the mid-saci'al artery. 



