PHYSIOLOGY, AND PATHOLOGY OF THE CHiMPANZ?:E. 425 



ligamentum nuchse is present. Owing to the greater forward 

 projection of the odontoid process, the check and middle odontoid 

 ligaments are more horizontal than in Man. The articular 

 processes cause more locking of the atlas and axis. The head has 

 a much more limited movement, and this is accompanied by a 

 greater upward mobility of the eyeballs. The carpal ligaments 

 are more complex than in Man. And the construction of the 

 joints of the pelvis and leg are such that the animal cannot stand 

 stiffly in a fully erect attitude without holding on to branches 

 above it. 



The mouth differs from tliat in Man in the greater number of 

 palatal rugae and in the characters of the tongue, although 

 Wood-Jones states that the tongue is like that in Man. The 

 pharyngeal musculature is similar in both, but the Chimpanzee 

 has the larger sinus of Morgagni. Man has only two muscular 

 coats in his oesophagus, but the Chimpanzee has an additional 

 inner longitudinal coat in its upper part. Man has three 

 muscular layers in his stomach, but the Chimpanzee has only 

 two ; and the inner coat is composed of oblique or circular fibres 

 in different parts. As regards the intestinal tract the most 

 striking differences are found in the rectum The Chimpanzee 

 has five enormous valvulaj conniventes running completely round 

 it, and the columns of Morgagni are very prominent longitudinal 

 folds running down to the lower end of the anal canal. When 

 the anus is dilated these columns are seen at once. No valves of 

 Bull connect the columns as in Man. The anus is prominent as 

 the gluteal regions are small, whereas the reverse is the case in 

 Man. 



The amount of lymphoid tissue in the intestinal mucosa is less 

 in the Chimpanzee than in Man, 



The liver and pancreas are practically the same in both. 

 The heart is small in the Chimpanzee, but its structure is as in 

 Man. The branches of the aortic arch take one of two forms, 

 and one of these varieties is as in Man. The subclavian arteries 

 give off well-marked spinal branches, and the branches of the 

 axillary artery come off as in the Cercopithecidge. iNo arterial 

 anastomoses exist round the scapula or elbow joint as they are in 

 Man. The vessels in the forearm form long parallel branches, 

 much as in the Lorises, and there are three palmar arterial 

 arches, whereas Man has only two. The branches of the 

 abdominal aorta are fewer than in Man ; and in my specimen 

 the femoral artery gave off branches which combine those of the 

 external iliac and femoral arteries in Man. The femoral artery 

 gives 0&. a saphenous artery to the foot, and the anterior tibial 

 artery courses differently from that in Man. 



In the venous system the chief differences from the condition 

 in Man are the freer intercommunications between the parts of 

 the portal circulation, the absence of a saphenous opening, the 

 ending of the cephalic vein in the lower end of the brachial veins. 

 and the presence of a large brachial vein instead of two vena? 

 comites of the brachial artery. 



