parts of soft
paraffin and vaseline with a few drops of lysol. This treatment should
be repeated daily until the acarus is destroyed and the animal has
regained its normal condition. The cages should be disinfected and all
neighbouring animals carefully examined, and any which show signs of
infection should be treated in a similar manner. Favus also attacks the
rabbit, and the typical spots are first noted around the base of the
ear.

Infection by _Coccidium oviforme_ is very common, without however
presenting any symptoms by which the infection may be recognised.
Usually the condition is only noted post-mortem, when the liver is found
to be studded with numerous cascating tubercles, which on examination
prove to be cystic areas crowded with coccidia. Sometimes too the liver
of a rabbit dead from some intentional or accidental bacterial infection
is found at the post-mortem to be marked by fine yellowish streaks and
small tubercles due to the embryos of _Taenia serrata_, while the cystic
form (_Cysticercus pisiformis_) is often noted free in the peritoneal
cavity, or invading the mesentery.

Abscess formation from infection with ordinary pyogenic bacteria occurs
naturally in the rabbit, and frequently the animal house of a laboratory
is decimated by an infective septicaemia due to _B. cuniculicida_.

The ~Mouse~ and ~Rat~ suffer from septicaemia, and from the cysticercus
form of _Taenia murina_; the cystic form (_Cysticercus fasciolaris_) of
_T. crassicollis_ has its habitat in their livers. These small rodents are
frequently infected with scabies, but if freely provided with clean
straw will clean themselves by rubbing through it. The mouse is also
attacked by favus, and the rat is often infected with _Trypanosoma
Lewisi_.

The ~Guinea pig~, like the rabbit, suffers from scabies and coccidiosis.
In addition it is often naturally infected with _B. tuberculosis_, and
it is a wise precaution to test animals as soon as they reach the
laboratory by injecting Koch's Old Tuberculin--0.5 c.c. causing death in
the tuberculous cavy within 48 hours.

The ~Monkey~ is naturally prone to tuberculosis, and should be injected
with 1 c.c. Old Tuberculin on arrival in the laboratory. The tissues of
the monkey also serve as the habitat for a Nematode worm parasitic in
cattle (_Oesophagostoma inflatum_) resembling the Anchylostomum, and
this parasite frequently bores through the intestinal wall, and
provokes the formation of small