522 COMPAEATIVE IJEUIIOLOGY. 



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 terminatioi^ of the S3rmiJathetic nerve is not always the 

 same, and while it often ends in a delicate filament, v/hich 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 NEUBX)LOGY. 

 RUMINANTIA. 



Not w iTuSTAunrxG the greater development of the coccyx in the ox, the 

 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 rabbit 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. Withrespect. 

 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 

 brear^.th of the oesophagus ; the latter organ is more amply supplied with nerves 

 than that of the horse. The superior oesophageal 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, v/hile the other, becoming more anterior, descends 

 the metacojpus, 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 cazic cource forms the internal 

 collateral nerve common' to both the digits.' 



In the nerve3 of the lumbo-sacral plexus there is httle to note of importance. 

 The dxyrsal 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 j it divides in the distal notch to form the posterior deep digital 

 ^nerves. , There is no. connecting btttnch between the external and internal 

 m:tatarcal nerves. 



