ANIMAL INOCULATION 211 



is made. The material may be inserted into this pocket 

 with a heavy platinum needle. Cutaneous inoculation is 

 made by shaving the skin and rubbing the material onto 

 the shaved surface or scratching with a scalpel or special 

 scarifier, but without drawing blood, and then rubbing in 

 the material to be inoculated. 



Intravenous injections are made with larger animals. In 

 rabbits the posterior external auricular is a convenient vein. 

 In larger animals the external jugular is used. 



Intraperitoneal, -thoracic, -cardiac, -ocular, -muscular injec- 

 tions, and injections into the parenchyma of internal organs 

 are accomplished with the hypodermic needle. In the case 

 of the first two, injury to contained organs should be care- 

 fully avoided. Intracardiac injection, or aspiration of the 

 heart to secure blood, requires considerable practice to be 

 successful without causing the death of the animal at once 

 through internal hemorrhage. In subdural injections into 

 the cranial cavity it is necessary to trephine the skull first, 

 while such injections into the spinal canal may be accom- 

 plished between the vertebra with needles longer and stronger 

 than the usual hypodermic needle. Occasionally animals are 

 caused to inhale the organisms, or are fed cultures mixed 

 with the feed. 



SECURING AND TRANSPORTING MATERIAL FROM 

 ANIMALS FOR BACTERIOLOGICAL EXAMINATION. 



If the site of the lesion is readily accessible from the 

 exterior, material from the living animal should be collected 

 with sterile instruments and kept in sterile utensils until the 

 necessary tests can be made. Testing should be done on 

 materia] as soon after collection as possible, in all cases, to 

 avoid the effects of "decomposition" bacteria. 



If the blood is to be investigated it may be aspirated from 

 a peripheral vein with a sterile hypodermic syringe of appro- 

 priate size or allowed to flow through a sterile canula into 

 sterile receptacles. The site of the puncture should be 

 shaved and disinfected before the instrument is introduced. 



Discharges of whatever kind should likewise be collected 

 in sterile receptacles and examined as soon as may be. 



