118 ANATOMICAL TECHNOLOQT. 



§ 280. (1) Freely Opening tJie AMomen.— This is sometimes, as 

 when collecting in the Held, the only practicable method. The ab- 

 domen is opened by a longitudinal incision a little dextrad of the 

 meson, never — as commonly directed — on the meson itself. A sec- 

 ond incision is to be made at a right angle with the first, extending 

 to the dextral margin of the abdominal cavity ; these two incisions 

 are shown in Fig. 76, bnt the transverse one should not cross the 

 meson. 



The specimen is to be placed in 52-67 per cent, alcohol, the hand 

 introduced, and the viscera lifted and moved slightly, so as to per- 

 mit the penetration of the liquid to all parts ; cotton may be inter- 

 posed. The liver especially should be displaced, and — unless its 

 preservation is especially desirable — most of it should be removed, 

 the cholecyst (gall bladder) being left. 



§ 281. This method is much more efficacious if combined with 

 the third, as follows : — 



The rectum is compressed so as to expel its contents per anum, 

 and the small intestine treated in like manner, if its contents seem 

 to be considerable. The stomach is manipulated and compressed 

 so as to expel its contents through the mouth. A slit about 1 cm. 

 long is then made in the free surface of the duodenum near the 

 stomach, and alcohol injected, first through the pylorus into the 

 stomach, and then into the small intestine, so as to fill both it and 

 the large. The escape of the alcohol from the anus may be pre- 

 vented by a plug of cotton. For all injections of alcohol, a rub- 

 ber bulb syringe is more convenient than one with a piston. After 

 injecting, it should be thoroughly rinsed out with water. 



The lungs may be filled with alcohol by passing a curved canula 

 attached to a rubber tube from the mouth through the glottis, or 

 by opening the trachea. 



§ 282. (2) Injection of 62-67 per cent. Alcohol into the Thorax 

 and Abdomen. — This is less efficacious than the other methods, but 

 may be adopted when it is desirable to mutilate a specimen as 

 little as possible, as in making a permanent preparation of an entire 

 animal. 



The incisions for the introduction of the canula should be made 

 obliquely, so as to leave a valvular orifice which is less apt to per- 

 mit the escape of the injected liquid. Both sides of the thorax 

 should be injected. Of course this method is more efficacious if 

 combined with the third. 



