POST-MORTEM EXAMINATION OF ANIMALS. 221 



pair of heavy, sterilized scissors, is made along the 

 scorched tracks on either side of the thorax. 



After this the whole anterior wall of the thorax may 

 easily be lifted up, and by severing the connections with 

 the diaphragm it may be completely removed. 



When this is done and the abdominal flaps laid back, 

 the contents of both cavities are to be inspected and 

 their condition noted without disturbing them. 



After this, the first steps to be taken are to prepare 

 plates or Esmarch tubes from the blood, liver, spleen, 

 kidneys, and any exudates that may exist. 



This is best done as follows : 



Heat a scalpel quite hot and apply it to a small sur- 

 face of the organ from which the cultures are to be 

 made. Hold it upon the organ until the surface directly 

 beneath it is visibly scorched. Then remove it, heat it 

 again, and while quite hot insert its point through the 

 capsule of the organ. Into the opening thus made insert 

 a sterilized platinum-wire loop, made of wire a little 

 heavier than that commonly employed. Project this 

 deeply into the tissues of the organ ; by twisting it 

 about enough material from the centre of the organ can 

 be obtained for making the cultures. 



As the resistance offered by the tissues is sometimes 

 too great to permit of a puncture with the ordinary 

 wire loop, Nuttall (Centralblatt fur Baderiologie und 

 Parasitenkunde, 1892, Bd. xi. p. 538) has devised for 

 the purpose a platinum- wire spear which possesses con- 

 siderable advantage over the loop. It is of the form 

 seen in Fig. 48. It is easily made by beating a piece 

 of heavy platinum wire into a spear-head at one end, 

 and perforating this with a small drill, as seen in the 



