162 



LOCALIZED ELECTRIZATION. 



office for peripheral ganglia, so often invoked for the purpose 

 of explaining certain paralysing functions, rests only upon arbitrary 

 hypotheses. The following is the most serious objection which 

 Schifif opposes to the suggestion of CI. Bernard. If it be sound, 

 he says, with regard to the sub-maxillary gland, it should apply 

 also to the ear of the rabbit, where we have equally the possibility 

 of a vascular dilatation, produced by the direct irritation of nerves. 

 But no one has discovered the smallest microscopic ganglion in 

 the ear of the rabbit, any more than in that of the dog, or of 

 man.^ 



(&). M. Schiff has endeavoured to simplify and to solve the 

 question of mechanism now under discussion, by admitting the 

 possibility of active vascular dilatation by longitudinal muscular 

 fibres. But it may be objected anatomically, that such instru- 

 ments of dilatation do not exist.^ 



At present, however, this plea seems to me to have lost its 

 force, since M. Gimbert, whose admirable researches into the 

 structure and texture of arteries I have already hail occasion to 

 quote, has discovered in some arteries the presence of numerous 

 longitudinal and oblique muscular fibres, interlacing with the 

 horizontal fibres. 



" Their direction (t\ie arterial muscular fibres), he says, " is 

 most frequently horizontal, but it may be oblique, or even longi- 

 tudinal." ^ 



He has shown the direction of these fibres in several figures, 

 of which I have reproduced one only, fig. 42, which shows a 



Hg. 42. — Longitudinal section of umbilical artery at the base of the cord. Enlarged 700 diameters, 



after Gimbert.^ 



' Schiff, loc. cit., torn, i., p. 271. 



^ M. Schiff appears to have abandoned 

 his hypothesis of the existence of longi- 

 tudinal muscles, doubtless on account of 

 this objection. He has written, indeed, 

 in one of his lectures, " Although the in- 

 strument of active dilatation at jiresent 

 eludes our means of investigation, nothing 

 has shown the impossibility of the pro- 

 cess." All that we can say, provisionally, 

 is that, while the mechianisra of con- 



striction is directly explicable by micro- 

 scopic examination of the vascular muscles, 

 the active dilatation appears to be ex- 

 traneous to the proper tissues of the ves- 

 sels, and to be effected by the intermedia- 

 tion of extra-vascular tissues. 



' Gimbert, loc. cit., p. 80. 



* I, I, Longitudinal muscular fibres ; 

 i, t, horizontal muscular fibres ; E, oiiter 

 coat ; M, middle coat ; I, inner coat. 



