1890.] 



The Superior Cervical Ganglion. 



381 



capable of producing primary contraction was much, greater than that 

 given by Dastre and Morat. On gradually increasing the strength of 

 the shocks we find with minimal shocks a slight paling of the lips and 

 gums, which only slowly disappears, so that the original pinkish 

 state of the mucous membrane is not regained for one to two minutes 

 after the end of the stimulation. As the shocks are gradually in- 

 creased in strength the paling becomes more marked, and the after- 

 paling of less duration ; with a certain increase in the strength of 

 shocks, the paling continues for a short time after the stimulation, 

 and then gives way to a slight flushing ; with further increase, the 

 duration of the after-paling diminishes and the after-flush increases, 

 so that soon the pallor gives way, even during the continuance ot 

 the stimulation, to intense flushing. After this, a slight further in- 

 crease in the strength of the shocks causes primary flushing. Marked 

 flushing is first produced in the anterior part of the lips and gums ; 

 a stronger current is required to produce it in the posterior part of 

 the lips and gums and in the hard palate. 



We have found a primary pallor with very considerable variation 

 in the strength of the current. Thus in one case primary flushing 

 was first obtained with the index of the secondary coil at 9 cm. from 

 the primary coil ; with the secondary coil at 18 cm., a slight, though 

 distinct, pallor was produced ; moreover, the after-flush produced, by 

 the stronger stimulus was considerably shortened by applying to the 

 nerve the weaker stimulus. In another case the secondary coil was 

 gradually shifted in successive stimulations from 20 cm. to 6 cm. 

 distance from the primary. In all the first effect was pallor ; with the 

 weaker stimuli this alone was obtained.* The shocks with the 

 secondary coil at 6 cm. could scarcely be borne onthe tongue; with 

 the secondary coil at about 15 cm. they could not be felt on the 

 tongue. 



Although some of the results which we have just mentioned do 

 not agree with those of Dastre and Morat, we wish to point out that 

 they do not conflict with, but rather confirm, the main contention of 

 these observers, viz., that the sympathetic contains both vaso-con- 

 strictor and vaso- dilator fibres for the bucco-labial region. 



And from the unequal effects of a moderately strong stimulus on 

 the different parts of the bucco-facial region, we may conclude that 

 the proportion of constrictor and dilator fibres for the different parts 



* Laffont (' Soc. de Biologie,' 1880, p. 341), on stimulating the uncut vago- 

 sympathetic in an atropinised dog, found with all strengths of stimulation primary 

 constriction followed by dilation, the primary constriction being briefer the stronger 

 the stimulation. Apparently, however, the paralysis of the inhibitory fibres of the 

 vagus by the atropin given was assumed, and actual observation on the point omitted ; 

 and Dastre (' Soc. de Biologie,' 1880, p. 348) attributes the previous pallor obtained 

 on stimulating the sympathetic to a slowing or cessation of the heart-beat. 



