Il8 BACTERIOLOGICAL LABORATORY TECHNIC 



culture is run into the peritoneal cavity, or under the skin. The 

 animal is carefully weighed, and it is watched from day to day. 

 If it dies an autopsy is made on it. 



Other methods consist in injecting fluid culture into the veins of 

 the ear, or into the peritoneum, by means of a sterile hypodermic 

 syringe. The autopsy should be made carefully; the animal should 

 be thoroughly wet with a solution of bichloride of mercury, then it 

 should be stretched over a pan, especially devised for the purpose, 

 or nailed to a board. The skin over the abdomen and thorax must 

 then be shaved and sterilized with a solution of bichloride of mer- 

 cury. The walls should then be seared in a line from the throat to 

 the pubes with a hot knife, and through this line a cut should be 

 made opening up the thoracic and abdominal cavities. 



By means of a hot knife spots must be seared on the various organs, 

 and with another sterile knife cuts should be made into the organs, 

 then through these cuts sterile platinum needles are thrust, and 

 then culture media are inoculated with them. Sometimes it is neces- 

 sary to remove bits of tissue from various organs and place them 

 in culture media. In the recovery of the tubercle bacillus from 

 animals this procedure is necessary. Great care must be taken in 

 making the culture and all tubes should be carefully stored. Often 

 it is of great importance to make smears on cover-slips as well 

 as cultures, from the heart cavities, liver, kidney, peritoneal cavity, 

 etc., and stain them directly with Jenner's stain. It is sometimes 

 necessary to inject cultures, or bits of nerve tissue from a rabies case 

 into the brain. To do this, remove, under strict aseptic precautions, 

 a button of bone from the skull by means of a trephine. 



Histological Methods. 



Sections of tissues from infected animals are often examined and 

 stained by appropriate methods. To demonstrate bacteria, the 

 tissues should be hardened in absolute alcohol, and imbedded in 

 celloidin, then cut into sections and mounted in the following 

 different ways: 



