692 THE SYMPATHETIC NERVES. 



The superficial cardiac nerve of the left side has, while in the neck, the 

 same course and connections as that of the right side. But within the 

 chest it follows the left carotid artery to the arch of the aorta, and ends in 

 some instances in the superficial cardiac plexus, while in others it joins the 

 deep plexus ; and accordingly it passes either in front of or behind the arch 

 of the aorta. 



4. BRANCHES TO BLOOD-VESSELS. 



The nerves which ramify on the arteries (nervi molles) spring from the 

 front of the ganglion, and twine round the trunk of the carotid artery. 

 They are prolonged on each branch of the external carotid, and form 

 slender plexuses upon them. 



Communications with other nerves. From the plexus on the facial artery is derived 

 the filament which joins the submaxillary ganglion ; and, from that on the middle 

 meningeal artery, twigs have been described as extending to the otic ganglion, as 

 well as to the gangliform enlargement of the facial nerve. Lastly, a communication 

 is established between the plexus on the carotid artery, and the digastric branch of 

 the facial nerve. 



Small ganglia are occasionally found on some of the vascular plexuses, 

 close to the origin of the vessels with which they are associated. Thus 

 lingual, temporal, and pharyngeal ganglia have been described ; and besides 

 these there is a larger body, the ganglion intercaroticum, placed on the 

 inner side of the angle of division of the common carotid artery. This body, 

 long known to anatomists as a ganglion, has been stated by Luschka to 

 have a structure very different from the nervous ganglia in general, and has 

 been named by him the "glandula intercarotica. " 



The ganglion intercaroticum was described by Luschka as presenting principally 

 a follicular structure, and regarded by him as being of a nature similar to the glan- 

 dula coccygea, which he had previously discovered. It appears, however, from the 

 researches of Julius Arnold, that the follicular appearances observed by Luschka, both 

 in this instance and in the coccygeal gland, were produced by arterial glomeruli seen 

 in section; and that the ganglion intercaroticum consists of numbers of those glome- 

 ruli gathered into several larger masses, and of dense plexuses of nerves surrounding 

 respectively the glomeruli, the masses, and the whole structure. Within those plex- 

 uses nerve-cells are scattered, but not in very great number. The ganglion is usually 

 about one-fourth of an inch long ; but, according to Luschka, may be divided into 

 small separate masses, and thus escape attention, or be supposed to be absent. 

 (Luschka, Anat. d. Menschen, vol. i. 1862 ; and Julius Arnold, in Virchow's Archiv., 

 June, 1865.) 



MIDDLE CERVICAL GANGLION. 



The middle ganglion (ganglion thyroideum), much the smallest of the 

 cervical ganglia, is placed on or near the inferior thyroid artery. It is 

 usually connected with the fifth and sixth spinal nerves, but in a somewhat 

 variable manner. It gives off thyroid branches and the middle cardiac 

 nerve. 



THYROID BRANCHES. From the inner side of the ganglion some twigs 

 proceed along the inferior thyroid artery to the thyroid body, where they 

 join the recurrent laryngeal and the external laryngeal nerves. Whilst on 

 the artery, these branches communicate with the upper cardiac nerve. 



THE MIDDLE CARDIAC NERVE (nervus cardiacus profundus v. magnus) of the 

 right side is prolonged to the chest behind the sheath of the common carotid 

 artery, and either in front of or behind the subclavian artery. In the 



