522 COMPARATIVE NEUROLOGY. 



communicate with these nerves by numerous filaments, and give 

 off several small twigs, which are lost in the cellular tissue on the 

 inferior face of the sacrum. 



The termination of the sympathetic nerve is not always the 

 same, and while it often ends in a delicate filament, which is 

 carried under the middle coccygeal artery, and unites with that 

 of the opposite side, it sometimes terminates in a filament which 

 communicates with the last pair of sacral nerves. 



COMPARATIVE NEUROLOGY. 



RUMINANTIA. 



NOTWITHSTANDING the greater development of the coccyx in the ox, tlie 

 spinal cord is not prolonged further backwards than in the horse ; nor is it 

 so in any of the animals which engage our attention, with the exception of 

 the rahbit and bird. 



The optic nerves and pituitary gland are larger, and the testes more separated 

 from the nates than in the horse. The cerebral convolutions are fewer in number 

 but larger, while the hemispheres themselves are larger posteriorly. With respect 

 to the cranial nerves the differences are not, as a rule, of sufficient importance 

 to claim notice here. We may, however, note that the jugular ganglion and 

 pharyngeal branch of the tenth nerve both are very large. The recurrent 

 nerves are separated from the pneumogastric trunk and carotid artery by the 

 breadth of the oesophagus ; the latter organ is more amply supplied with nerves 

 than that of the horse. The superior resophageal branch chiefly supplies the 

 rumen, the inferior the other compartments. The spinal accessory divides into 

 two branches, superior and inferior, the latter supplying the muscles of the 

 infero-lateral cervical region. 



The radial nerve sends two cutaneous branches downwards, one of which 

 becomes lost at the carpus, while the other, becoming more anterior, descends 

 the metacarpus, and supplies the dorsal nerves of the digits. The median and 

 cubital nerves are not connected at the carpus, but continued downwards, the 

 former as the internal, the latter as the external metacarpal nerve, each supply- 

 ing its respective digit ; about the distal end of the metacarpus, a branch from 

 the internal passes across to join the external nerve, while lower down a second 

 branch from the internal nerve forms the external collateral nerve of the inner 

 digit, and still lower a third branch from the same source forms the internal 

 collateral nerve common to both the digits. 



In the nerves of the lumbo-sacral plexus there is little to note of importance. 

 The dorsal nerves of the digits are given off by the musculo-cutaneous nerve. 

 The anterior tibial nerve sends a branch down the anterior groove in the 

 metatarsus ; it divides in the distal notch to form the posterior deep digital 

 nerves. There is no connecting branch between the external and internal 

 metatarsal nerves. 



