UTILIZATION OF ANIMALS FOR BACTERIA 271 
White mice and rats are usually inoculated in the loose subcutaneous 
tissue at the base of the tail. The needle should pass anteriorly and 
somewhat obliquely to avoid injury to the spinal cord. 
Core of Animals.— Gumea-pigs and rabbits are very susceptible to 
"snuffles" and frequently perish from contagious pneumonia and 
other epizootics of the respiratory tract.' The first symptoms are 
usually nasal discharge and a muco-purulent exudation from the eyes. 
Such animals should be killed at once and their cages thoroughly 
sterilized. Animals in adjacent cages should be quarantined. 
Inoculated animals are best kept in separate cages wholly apart 
from the healthy stock. If they become moribund it is better to 
chloroform them and perform the autopsy at once; fresh, uncon- 
taminated cultures may be obtained only at this time. Cultures of 
bacteria obtained from the tissues of guinea-pigs should be interpreted 
with great caution. Holman- has found streptococci, pneumococci 
and other bacteria to be not uncommon even in uninoculated animals. 
If animals are permitted to die, frequently several hours intervene 
before an autopsy is performed, and postmortem bacterial invasion 
of the tissues and blood stream is usually a disturbing factor. Infected 
material is obtainefl from animals with the same precautions and 
technique as those for a human autopsy. 
1 Theobald Smith: Jour. Med. Res., 1914, 29, 291, for discussion. 
2 Jour. Med. Res., 1916, 35, 151. 
