AMPHIBIA. 39 



of this with the ninth, appears as if it were proceeding from the ninth to give branches 

 to a long muscle analogous to the sterno-mastoid, and then send a branch to join one 

 from the first and second cervical nerves, and terminate in the sterno-thyroideal 

 muscle, one attached to the posterior part of the oesophagus, and one at the side 

 of the neck. The ninth arises from the track of the pyramidal body, and divides into 

 an anterior and posterior trunk ; the anterior becomes connected with the par vagum 

 and accessory ; the anterior terminates on the genio-hyoideal muscle, the genio-glossal, 

 and the hyo-glossal, after sending one, which may be the accessory, to terminate on 

 the sterno-thyroideal muscle, and that attached to the posterior surface of the 

 ossophagus ; the posterior trunk joins the posterior trunk of the first cervical nerve. 

 In the snake, it receives a branch from the trunk of the par vagum and from the hard 

 portion of the seventh, after this has communicated with the first cervical nerve ; it 

 gives several branches to the muscles of the tongue and throat, and one that reaches 

 to the end of the tongue, and one to communicate with branches of the third trunk 

 of the fifth issuing from the inferior part of the lower jaw. 



SPINAL CORD. The spinal cord in the turtle is continued from the oblong 

 medulla to the end of the tail ; it is somewhat flattened, and is larger in the regions 

 giving off the largest nerves. In the turtle, the first two cervical nerves are formed 

 entirely of filaments from the anterior surface of the cord. The anterior bundles of 

 all the other cervical nerves are much larger than the posterior, those of the thoracic 

 smaller, and those of the sacral rather larger. Each posterior bundle is formed into 

 a ganglion, and is joined by the anterior for forming a nerve. In the crocodile, the 

 spinal cord reaches to the extremity of the tail, and each posterior bundle of fibrils 

 forms a ganglion. In the snake, it is continued of nearly the same thickness through- 

 out until it reaches the tail, and it is then extended to the end of the tail by becoming 

 gradually smaller. The cineritious matter contained within it appears very full of 

 vessels after its minute injection with colouring matter. The cord gives off anterior 

 and posterior bundles of nerves, which are very close to each other, and the anterior 

 are rather larger than the posterior ; the posterior is formed into a ganglion, and at its 

 anterior point the anterior bundle becomes connected with it for the completion of 



