74 
DR. C. E. BEEVOR AND MR. V. HORSLEY ON THE EXCITABLE 
To this point we shall subsecpiently return. We may now mention the movements 
which are credited with being bilaterally represented, and we shall arrange them in 
classes, the justification for which will subsecpiently appear. 
Credited as Bilateral. 
Movements of Trunk Muscles [i.e., 
Ptectus, abdominis, &c.) 
Movements of Tongue 
Conjugate deviation of Eyes 
Turning of Head 
Retraction of Angle of Mouth 
Pursing of Lips 
Onening of Eyelids | Identical move- 
Closino’ of Eyelids J ment 
Pouting of Lips 
Mastication 
Swallowing [i.e., movements of soft 
palate) 
Adduction of vocal cords 
Class—I. Movements asserted to he hilateml, hut not actually so. 
Movements of the Trunk Muscles. —The muscles of the trunk liave above all others 
in the body been commonly supposed to be bilaterally associated in action. This is, 
however, cpiite contrary to observed fact. We have never seen any movement of 
both recti or oblicpie abdominis follow excitation of the fibres for the trunk muscles 
in the capsule, although we invariably saw movement restricted to the muscles of the 
opioosite side, notably the rectus. We have observed this to be the case clinically, 
and believe that the statements made in the opposite direction rest upon imperfect 
examination. Further confirmation is to hand in the description given by Professor 
ScHArEE,"^ and one of us, of the results of excitation and ablation respectively of the 
“ trank areas ” in the marginal gyrus, from which it appears that the same unilateral 
representation was discovered to exist. 
Movements of the Tongue. —As we are specially investigating the cortical represen¬ 
tation of these movements, we desire to defer the detailed observation of the capsular 
fibres subserving the same, until the former is completed. 
Conjugate Deviation of the Eyes and Turning of the Head. —We have already 
mentioned the movements of the eyeballs, and wm now intend to strengthen what is 
said on p. 73. 
* Hoesley and Schafer, ‘Phil. Trans.,’ B, vol. 179, 1888, pp. 10 and 14. 
> Class I. Not bilateral, md. inf 
i 
y Class 11. Imperfectly bilateral. 
j 
|> Class III. Truly bilateral. 
J 
