ABDOMINAL VISCEBA. 375 



§ 710. Exposure. — Determine the three following landmarks by 

 pressing on the various parts of the abdomen where they are indi- 

 cated (Fig. 76) : (A) The ventrimeson by finding the xiphisternum 

 (Fig. 30, 72, § 228) ; (B) the caudal margin of the 12th rib (Fig. 30, 

 72) ; (O) the pubis (Fig. 51, 76, § 228). 



After having determined the three landmarks, the hair should 

 be moistened and parted as directed above (§§ 354, 599) ; then the 

 incisions should be made along the lines indicated in Fig. 76. 

 Make the incisions in the manner described for abdominal transec- 

 tion (§ 237). Reflect the four flaps, being careful not to tear any of 

 the thin membranes— urocystic and hepatic ligaments, etc.— attached 

 along the meson. 



Preparation and Exposure -Fig. 77.— The cat was fed a mod- 

 erate amount of meat about an hour before it was killed with 

 chloroform. After death it was placed dorsicumbent on the dem- 

 onstration board, the head fastened with the pointed holder (see 

 Fig. 77), and the limbs secured laterad with the straps. 



After parting the hair (§ 354), an incision was made from the 

 angle of the mouth on the right, along the middle of the side of 

 the neck, thorax and abdomen, then on the left side as far cepha- 

 lad as the angle of the mandible. The mucous membrane and 

 the thick muscles on the side of the face and neck were cut at 

 the same level as the skin, and the right mandibular ramus dis- 

 jointed with the arthrotome. The hyoid bone (Fig. 30, § 224) was 

 cut, and the left coronoid process (Pig. 61) broken with nippers ; 

 this made it possible to turn the mandible to the left so as to expose 

 the pharynx and the floor and roof of the mouth. 



The ribs and soft parts of the abdominal and thoracic wall were 

 then cut with scalpel and nippers at the same level as the incision 

 in the skin. The mediastinal septum and the diaphragm were cut 

 with scissors close to the ventral wall, and the entire ventral wall 

 of the body was removed. 



In some specimens the ovary {ovarium) and Mdney (ren) will 

 not appear without displacement of the intestines, and in old ani- 

 mals the thymus may be absent (Fig. 77, Cp. thym.). The following 

 parts will be exposed (Fig. 77) : — 



Description of rig. 77.— Cardia, az. — Heart. Cholecystis, az. 

 — Gall bladder. Cornu Uteri. — Left horn of the uterus. Costae. — 

 Eibs (13). The cut ends are shown on each side of the thorax. 

 Cp. thym.. Corpus thymicum, as. — Thymus body or gland. Dia- 



