186 



ANATOMY OF VERTEBRATES. 



•10 



sympathetic send branches to the semilunar ganglion, to the 

 renal, spermatic, and aortic plexuses.' 1 The uterine nerves are 

 derived from the hypogastric plexuses ; they accompany the ves- 

 sels along the broad ligaments ; most separate therefrom before 

 reaching the uterus : others retaining a plexiform arrangement 

 about the vessels, show minute ganglia in their course, fig. 140. 

 In long-tailed Mammals the sympathetic is continued beyond the 



azygous ganglion on the caudal artery, 

 sometimes as a pair of cords (jaguar). 2 

 In all Mammals examined to this end 

 filaments of the sympathetic have been 

 traced, with those of the third and fifth, 

 to the ophthalmic ganglion, sending off 

 the ciliary nerves: andthegeneral result 

 of this branch of Comparative Neuro- 

 logy tends to establish the conclusion 

 that every myelencephalic nerve con- 

 tains some proportion of filaments from 

 the sympathetic, whilst every sympa- 

 thetic ganglion, reciprocally, receives 

 some filaments from the myelencephalic 

 system. These, however, are so mo- 

 dified as to be unequal to the trans- 

 mission of volitional influence to the 

 organs mainly supplied from the sym- 

 pathetic ganglions : but they may be 

 the media of conveying thereto invo- 

 luntary influence and the stimulus of 

 violent emotions : and, conversely, they 

 may convey the sensations of pain from 

 the irritated ganglion to the encepha- 

 lon. The sympathetic system mainly 

 governs nutritive and secretive processes and involuntary move- 

 ments; it influences the contractile power of bloodvessels, the 

 coats of which, in all Mammals, show a considerable plexiform 

 supply from the sympathetic system. 



§ 213. Organs of Touch. — In considering such parts in Mam- 

 malia,, the sensibility of their highly organised integument, exem- 

 plified by its agitation in the horse on the contact of a fly, must 

 be distinguished from the special adaptations of parts or appen- 

 dages of the skin for purposes of tactile exploration. Increased 

 supply of bloodvessels and nerves to a part of the 



1 liv. p. 117. 2 lb. p. 117. 



Small ganglion from posterior wall of 



the cervix of an impregnated uterus 



of a Cow. lxxvii". 



tegument 



