568 APPENDIX. 



assistants holding it in a vertical position, the foot resting npon a table, 

 stool, or solid block of wood. Push in, as deeply as possible, the blade 

 of the scalpel between the sensitive and the horny wall ; move it about 

 from right to left, and make it follow the contour of the latter. By 

 means of the chisel and the hammer, split the wall into four or five 

 fragments by a convenient number of vertical incisions. When the 

 wall has been thus divided into several segments, detach each of these, 

 by inserting the point of the chisel into one of the incisions, and, using 

 this instrument as a lever, throw back the portion of horny substance 

 to the right or left. The flap of the opposite side is then raised and 

 separated from the subjacent tissues. Their complete detachment will 

 be effected by means of the strong forceps, and by twisting them with 

 considerable force, the portion of the wall will be torn from the sole. 

 In order to uncover the latter, pass the blade of the scalpel between the 

 upper face of the horny arch and the sensitive sole ; push the point of 

 the chisel into the space thus opened, raising lightly the external edge of 

 the sole. Then seize the latter with the forceps, and detach it as well as 

 the frog, by a wrench, giving the instrument a vigorous movement back- 

 wards and forwards, the assistants holding the limb tightly and with ii 

 force opposed to that of the operator. 



THE ORGANS OF DIGESTION. 



The Mouth. — The whole of the mouth ought to be examined by an 

 antero-posterior and vertical section of the head. 



The Palate. — Separate the head from the trunk ; then saw through 

 the ramus of the inferior maxillary bone above the angle of the jaw and 

 the crown of the last molar tooth, in such a manner as to pass between 

 the velum palati on the one side, the base of the tongue on the other, 

 and leave this latter organ adherent to the lower jaw. Separate the 

 lower jaw from the upper, cutting the masseter and alveolo-labial 

 muscles, and in this way expose the palate and the velum palati, upon 

 which it will then be possible to execute easily the special dissection 

 necessary for their study. For the palate, these dissections consist in 

 raising the mucous membrane which conceals the deep venous plexus, 

 and in the partial removal of the latter so as to see the artery and the 

 palatine nerves. 



The Tongue. — 1. Make, by means of a strong saw without a back, an 

 antero-posterior and vertical section of the head, to study the general 

 disposition of the tongue. 2. Remove from another head the lower jaw, 

 leaving the tongue in the maxillary space, so as to examine the external 

 conformation of the organ. 3. Upon another head intended for the 



