322 BACTERIOLOGY. 



want of sufficient haemoglobin; but if sterile rabbit, 

 pigeon, or human blood be added to these media trans- 

 plantation may be indefinitely performed, provided it is 

 done every three or four days. Cultures may remain 

 alive up to seventeen days in the ice-chest. 



The Detection of the Influenza Bacillus in Sputum. 

 When it is desired to obtain cultures of the bacillus 

 of influenza for diagnostic purposes from material sus- 

 pected to contain this organism, it is advisable from 

 the start to make use of plate cultures, the best medium 

 being nutrient agar freshly smeared with rabbit's blood. 

 The sputum, blood, or other substance to be examined 

 is streaked across several plates of blood-smeared agar, 

 so as to leave on some considerable of the material and 

 on others merely the slightest trace. An easy way to 

 get blood when a large number of plates are to be made 

 is to kill a rabbit and autopsy it immediately. The 

 skin is turned back from the chest and the thorax 

 opened aseptically. The heart is cut off at its base 

 and dragged over some twenty to forty plates, as de- 

 sired. The blood collecting in the thorax is used to 

 smear the agar in a number of tubes, which can be kept 

 in the ice-chest until needed. With a little skill blood 

 .can be withdrawn aseptically from the ear vein of a 

 rabbit by means of a glass tube armed with a hypo- 

 dermic needle. 



When cultures are made from sputa the endeavor 

 should be made to collect the expectoration which comes 

 up naturally, so as not to get any more than necessary 

 of the mouth bacteria. If the mouth is at all foul, it 

 should be cleansed before gathering the sputum. Cul- 

 tures should be made as soon as possible after obtaining 

 the material. The plates are put in the incubator for 



