ON THE ORGANIC FUNCTIONS. 865 



medulla oblongata, a centre that, like the preceding, .is in a constant state 

 of activity, and is influenced in a manner similar to the respiratory and vaso- 

 mctor centres 'hence in dyspnoea the pupil dilates, and the vessels distributed 

 to the eye contract. 3. Secretory fibres for the salivary glands, irritation 

 of which contracts the vessels and modifies the characters of the secretion, 

 whilst section is followed by dilatation of the vessels. 4. Fibres possessing 

 an accelerating, and others exerting a depressing influence on the heart. 

 The former, according to MM. E. and M. Cyon, emerge by the third branch 

 of the inferior cervical ganglion ; whilst the first and second branches con- 

 stitute the roots of the depressor nerve. 5. Fibres passing to the central 

 cerebro-spinal organs, which reflectorially stimulate the nerves retarding the 

 action of the heart. As regards the thoracic portion of the sympathetic 

 trunk, Otto Nasse 1 and Bernard only obtained negative results from its di- 

 vision or excitation. The superior thoracic ganglion gives accelerator fibres 

 to the heart. The plexus cardiacus, arising from the thoracic sympathetic, 

 also receives branches from the vagus and the depressor nerves. The splanch- 

 nic nerves, which arise from the lower six thoracic ganglia, contain fibres exert- 

 ing an inhibitory, and others exerting an exciting influence 2 over the move- 

 ments of the intestine; secretory fibres acting on the kidneys (Bernard); 

 vaso motor nerves influencing the calibre of the whole abdominal system of 

 vessels; 3 and lastly, centripetal fibres exerting reflectorially an inhibitory in- 

 fluence on the action of the heart. The abdominal portion gives off numer- 

 ous branches which aid in forming the coeliac, meseuteric, renal, suprarenal, 

 spermatic, and hypogastric plexuses, and these, when irritated, occasion move- 

 ments in the parts to which they are distributed, as the intestine (small and 

 large), bladder, ureters, uterus, vesiculse seminales, spleen, etc., partly by 

 their direct action on the muscular fibres, partly by modifying the supply of 

 blood to them.* Of the ophthalmic ganglion ( 490), the branches are dis- 

 tributed, not merely to the iris, whose radiating fibres are made to contract 

 through their instrumentality, as already explained ( 618); but also to the 

 vascular apparatus of the eyeball, and especially to the ciliary processes, 

 which seem to possess a sort of erectile character. The otic ganglion, which 

 communicates with the third division of the Fifth pair and with the Glosso- 

 pharyngeal, may be considered, from the distribution of most of its branches 

 to the tensor tympani and circumflexus palati muscles, as ministering to the 

 exercise of the sense of Hearing, in somewhat the same mode that the oph- 

 thalmic ganglion seems to do to that of vision ( 645). The spheno-palatine 

 ganglion (Fig. 259, /), whose connections are with the Fifth and the Facial 

 nerves, seems in like manner to minister, by the distribution of its branches 

 on the mucous membrane of the nasal cavity and the palate, to the senses of 

 Smell and Taste. It has been shown by Prevost 5 to be purely sensory in 

 its function. Of the submaxillary ganglion, which also is chiefly connected 

 with the Fifth and the Facial nerves, the branches proceed almost entirely to 

 the Submaxillary gland, and according to Pfliiger 6 and Palladino, 7 terminate 

 in the gland-cells. 6. The fibres which arise from the ganglia on the pos- 

 terior roots of the Spinal nerves (if really belonging to the Sympathetic sys- 



1 Essays on the Physiology of the Movements of the Intestine. Pamphlet, 1806. 



2 Pfliigor, Nasse, Inc. cit. The splanchnic nerves (Bidder, Reichert, and Dubois- 

 Reymond's Archiv, 1869, p. 472) in the cat contain three kinds of fibres, viz., 1, 

 Broad medullated fibres, often collected into fasciculi ; 2, Slender medullated fibres ; 

 3, Slender Remak's fibres. 



3 v. Bezold, Untersuch. passim Cyon, and Ludwig, Arbeiten, etc , 1867. 

 * See Nasso, loc. cit. 



6 Brown-Sequard's Archives de Physiologic, torn, i, p 207. 



6 Loc. cit. ' 7 Abstract in Centralblatt, 1873, p. 782. 



