132 ANATOMICAL TECHNOLOGY. 



325. The foregoing is the method followed in making the transections shown in 

 Fig. 99 and 100. The following modifications may be desirable : 



1. The animal should be bled, when anaesthetized, as directed in 279. 



2. Probably sawdust would be better than hay for support during the freezing. 



3. The freezing was done in winter, but artificial cold might be produced at any time. 



4. More satisfactory results might be reached by making seciions of only part of a sin- 

 gle individual. For example, the thoracic transections would be more true to nature if 

 the lungs had been filled with water from the trachea ; this, however, would have spoiled 

 the neck. In like manner the stomach and intestine or other hollow organs could be 

 distended to their normal size. 



5. For the middle region of the abdomen, including the intestines and part of the 

 uterus and urocyst, a more satisfactory result might be reached by filling those organs 

 with water, and keeping up the pressure during the freezing. A sharp broad-bladed knife 

 could be used to transect the abdomen ventro-dorsad, and a narrow-bladed saw used for 

 dividing the vertebrae. 



326. Frozen Dissections. While frozen sections display the actual relative posi- 

 tion of organs which lie in a given plane, they are unsatisfactory for the same reason that 

 microscopic sections often are : it is rare that a complete view is afforded of any aspect of 

 an organ. Hence we believe that for many purposes there should be a combination of 

 freezing with ordinary dissection. For example, with a frozen cat, most of the thorax 

 could be removed with the saw. Then, before thawing took place, all the rest of the tho- 

 rax could be cut or nipped away so as to expose the entire cephalic surface of the dia- 

 phragm, with the oesophagus, great vessels and nerves projecting for a short distance. 

 The pelvic region could then be removed, and the preparation mounted in strong alcohol 

 so as to retain it* 1 form. 



327. Flexible Preparations of Muscles. Dr. Thomas Dwight has published (1) the 

 results of experiments by himself and others. We are unable to contribute anything to 

 the subject. 



328. Preparation of Hollow Viscera. Aside from preserva- 

 tion like other soft parts, the stomach and caecum, the lungs, the 

 urocyst (urinary bladder), and cholecyst (gall bladder) may be pre- 

 pared by permanent inflation with air or alcohol so as to display 

 their size, form and subdivisions with more or less of their texture. 



Since the stomach is most frequently prepared in this way, the 

 following directions apply more directly to it, but they may be 

 readily modified for the other organs named. The parts of the 

 stomach are shown in Fig. 81. 



329. Removal. The viscus should be removed from the body 

 as soon as possible after death. If, however, the stomach or cae- 

 cum has been freed from its contents as described in 283, the 

 removal may be longer delayed. 



There should be left attached to the viscus a portion of each 

 canal continuous therewith, about 5 cm. long if possible. With 

 large specimens this length may be greater, and with small ones it 

 must sometimes be less. To secure so much of the oesophagus of 



