126 LABORATORY BACTERIOLOGY 
and the four corners of the periosteum reflected or pushed back. 
By the aid of a trephine a small button of bone is easily re- 
moved, leaving the dura mater exposed. With a hypodermic 
syringe a drop or more of the rabid brain suspension is injected 
beneath the dura, the periosteum is replaced, the skin carefully 
sutured and disinfected, and the rabbit returned to its cage. 
As soon as the influence of the anesthetic has passed off, the 
rabbit shows no appearance of discomfort. If the operation 
is performed in the forenoon, the animal partakes of its eve- 
ning meal with the usual relish. The inoculation wound heals 
rapidly and the rabbit exhibits every appearance of being in per- 
Ject health until the beginning of the specific symptoms, which 
occur ordinarily in from 15 to 30 days, usually in about 20 days 
after the inoculation. Occasionally the symptoms appear earlier 
than in 15 days, and in some cases the rabbits are not attacked 
for from 1 to 3 months. 
The symptoms following the inoculations have in our experi- 
ence been quite uniform, the only pronounced difference being 
in the length of time the rabbits lived after the initial manifes- 
tation of the disease. The fact should be clearly stated that 
rabbits do not ordinarily become furious. In some instances 
they are somewhat nervous for a day or two preceding the 
paralysis. There appears to be a marked hyperzesthesia. 
Usually the first indication of the disease is a partial paralysis 
of one or both hind limbs. This gradually advances until the 
rabbits are completely prostrated, the only evidence of life 
being a slight respiratory movement. The head occupies dif- 
ferent positions. In some it is drawn back as in tetanus; in 
others it is drawn down, with the nose near the fore legs; and 
in still others it is extended as if the animal were sleeping. 
The period of this complete paralysis varies from a few hours 
to a few days, but ordinarily it does not exceed 24 hours. 
Although the animals are unable to move voluntarily, there is 
usually a reflex action‘ of the limbs until a very short time 
before death. 
