TRANSACTIONS OF THE SECTIONS. 679 



couffh and a struggle. In the recent investigation it was observ- 

 able that when the neivus vagus was divided, mechanicahrritation 

 applied to the upper end of the divided nerve produced the same 

 signs as when the nerve was entire. Every repeated compres- 

 sion of this nerve (as was also the case with the seventh) pro- 

 duced corresponding respiratory struggles ; whdst a unitorm, 

 uninterrupted compression caused no repetition of the phaeno- 

 raena. An additional argument in support of the opinion that 

 these effects are independent of any sensible property in the 

 nerve itself is furnished by the fact that Dr. Marshall Hall has 

 found precisely similar effects to occur in the turtle after its de- 

 capitation, on pricking the lateral spinal nerves, whether of the 

 sentient or motory class. 



3. Experiments upon the Spinal Accessory Nerve.— Ihxs. 

 nerve having been pricked without any response, was then 

 slightly pinched and scraped ; when the sterno-maxdlans mus- 

 cle, the levator humeri, and other muscles of the neck exclu- 

 sively were seen to contract at each application of this mecha- 

 nical irritation. But when the forceps was applied firmly, and 

 continued a few moments, similar effects were produced as with 

 the vagus and the seventh. The branches of this nerve appeared 

 to be equally destitute of sensibility with the root. The com- 

 pression of the upper end, after dividing this nerve below its 

 bifurcation, was followed by no effects, unless the pressure was 

 made opposite the giving off of the anterior branch, when the 

 same phenomena occurred as were exhibited m the entire nerve. 



4 Experiments upon the Glosso- Pharyngeal Nerve.— V^h^n 

 this nerve was pricked, scraped, or divided, no response was ob- 

 served The muscles of the root of the tongue were most pro- 

 bably set in motion by the compression of this nerve at inter- 

 vals; but no opportunity occurred of bringing this part ot the 

 tongue into view. Neither in its entire nor divided state did any 

 struggle arise from the continued compression of this nerve, 

 which is therefore regarded as one simply of muscular motion. 



5 Experiments upon the Ninth Nerve.— The sensible sur- 

 face of the tongue is supplied by the ganglionic portion of the 

 fifth nerve, whilst the muscles of its fore part are furnished with 

 branches from the ninth nerve. No sign of sensation was 

 evinced by mechanically irritating the trunk of this nerve, and 

 its division was unattended with any sign of feeling or pain. 

 But upon pinching it slightly at intervals, those muscles which 

 it supplies, on the same side of the tongue, were convulsed. It 

 the nerve was forcibly compressed, a slight gulp followed. W hen 

 the nerve was divided, pinching the upper end of it was not fol- 

 lowed by any muscular contractions. 



