542 A MANUAL OF BACTERIOLOGY 



is reproduced in rabbits, with paresis of the hind legs and death in 

 from sixteen to twenty-one days. The Negri bodies are absent, 

 the course of the disease differs somewhat from rabies, and the 

 B. pyocyaneus can be isolated from the brain and blood. 



Diagnosis of Rabies 



In a case of suspected rabies in a dog the animal should not be 

 killed immediately, but should be kept under observation until 

 it dies, or for three or four weeks, and then killed. 



1. Moderately thin smears on slides are made from (a) the cortex 

 in the region of the fissure of Eolando (the crucial sulcus in the 

 dog), (b) the hippocampus major, (c) the cerebellum. They are 

 dried in the air, fixed for five minutes in methyl alcohol, and then 

 stained in weak Giemsa (1 drop stain, 1 c.c. distilled water ; with 

 1 drop of 1 per cent, potassium carbonate solution to every 10 c.c. 

 of the dilute stain) for three hours. The stained films are then 

 washed in running tap-water for one to three minutes, dried with 

 filter-paper, and examined for the Negri bodies. 



Or the moist films may be fixed in methyl alcohol, and without 

 drying stained for one minute in a mixture of 10 c.c. distilled water, 

 3 drops of a saturated alcoholic solution of basic fuchsin, and 2 c.c. 

 of Loffler's methylene-blue. Eosin-methylene-blue mixtures may 

 also be used. 



The cytoplasm of the bodies stains orange, pink, red, or magenta, 

 the central nuclei are granular, and appear bluish or purplish. 



Luzzani considers that the Negri bodies can generally be well 

 seen in teased up fresh material unstained. It is stated that structures 

 resembling the Negri bodies may be present in the brain after death 

 from snake-bite. s < 



2. If the Negri bodies cannot be detected, inoculation should 

 be performed. The brain should be removed as soon as possible, 

 and if it cannot be manipulated immediately, should be placed 

 in sterile glycerin. From the middle of the floor of the fourth 

 ventricle a small piece about the size of a pea is removed ; this is 

 triturated and thoroughly emulsified in a sterile watch-glass by 

 means of a sterile glass rod with a bulbous end, a little sterile broth 

 being used to make the emulsion, and sufficient being added to 

 measure about 10 c.c. The hair on the head of a good-sized rabbit 

 is cut close, the animal is anaesthetised with ether, the skin on the 

 scalp reflected and a trephine hole made through the skull. The 

 centre of the trephine hole should be in the middle line, and on 



