ON THE ORGANIC FUNCTIONS. 869 



are seen in the vessels of the submaxillary gland when the chorda tympaui, 

 and in those of the penis when the uervi erigentes are stimulated. In the 

 latter case, if the nerves of both sides be cut, erection of the penis on sexual 

 excitement or by mechanical irritation of the sensory fibres in the pudendal 

 nerves is rendered impossible; yet if the distal extremities of the nerves be 

 irritated, the corpora caveruosa swell, and the copious flow of bright-colored 

 blood that follows an incision into them, shows that the circulation has been 

 greatly increased in activity. Claude Bernard 1 was at first disposed to admit 

 a direct dilating action of the nerves, and SchifF seems still to believe in the 

 possibility of such an influence. It involves, however, the view that mus- 

 cular fibres can be caused to elongate by irritation of their nerves, which is 

 contrary to all analogy. Others have suggested that the phenomena are 

 due to the contraction of the small veins, or in the case of the penis, to con- 

 traction of the trabeculte of the corpora caveruosa impeding the return of 

 blood ; but against this it has been shown that erection does not follow 

 ligature of the principal veins. M. Legros 3 again believes that they are 

 due to an exaggeration of the ordinary peristaltic action of the smaller 

 arteries, but it is not easy to understand how this could act in the absence of 

 valves. It is not improbable that two conditions co-operate in producing 

 the increased flow of blood in the instances adduced above. On the one 

 hand, as is especially seen in the case of the submaxillary gland, irritation 

 of the chorda tympaui may augment the attraction of the tissue of the 

 gland for the blood, and thus act in producing a vis afronte, and on the other, 

 as occurs more particularly in the case of the penis, the nervi erigeutes exert, 

 when stimulated, an inhibitory influence over the ordinary vaso-motor and 

 constricting nerves exactly comparable to that of the vagi over the move- 

 ments of the heart. 



717. It can only be through the Nervous System that the Muscular 

 apparatus of Organic life is acted upon by states of Mind. Although no 

 exertion of the Will can produce any effect upon any part of it, yet there are 

 various organs whose muscular walls are influenced on the one hand by 

 Emotional states, and on the other by the state of Expectant Attention. 

 The Heart sympathizes so much with the emotions, that the language of 

 almost all civilized nations refers to it as the seat of the " feelings" ( 241 

 etseq.); but we have as yet no certain evidence whether this influence is 

 transmitted through the Sympathetic or through the Pneumogastric nerve. 

 The former seems the more probable channel, when we bear in mind that it 

 can be through the sympathetic alone that those alterations in the diameter 

 of the bloodvessels take place which give rise to the blush of modesty or 

 shame, or to the pallor which alternates with this in many states of mental 

 agitation.* So, again, the influence of Emotional states is strikingly mani- 

 fested in the production of the peculiar turgesceuce of the Erectile tissues 

 ( 276) ; and here we have a striking example of the utter powerlessuess of 

 the Will in the well-known fact, that no amount of sexual desire will produce 



1 C. Bernard, Lecons sur les Liquides de 1'Organisme, t. i, p. 230; and Revue Sci- 

 entih'que, 1872, p. 119. 



2 M. Schiff, De 1'Inflammation, 1873. 



3 Ch. Legros, Des Neri's Vasumoteurs, The-;e, Paris, 1873, p. 67. For other papers 

 bearing on this subject, see Eekhard, Beitrage zur Anatomic, Abhand. vii, 1863 ; 

 Loven, Ludwig's Arbeiten, 1866, p. 1 ; Kolliker, Wurzburger Verhandlungen, Bd. 

 ii ; Goltz, Pfluger's Archiv, 1873, p. 346; Brown-Sequard, Le9ons sur les Nerfs 

 Vasomoteurs, pp. 25-65; v. Wittich, Virchow, Archiv, 1866, t. xxxvii, p. 93; 

 Heidenhain, Ptiiiger's Archiv, Bd. v, p. 40; Vulpian, L'Appareil Vasomoteur, 1875, 

 p. 160. 



4 The pallor of extreme fear or terror is probably due rather to a state tending to 

 Syncope, arising from a partial failure of the Heart's action. 



