card index system. The card further
provides space for notes on the course of the resulting infection, and
carries on the reverse the weight and temperature chart (Figs. 164 and
165).

[Illustration: Fig. 164.--Front of inoculation card.]

~Preliminary Inspection and Examination.~--The preliminary examination
should comprise observation of the animal at rest and in motion; the
appearance of the fur, feathers or scales, inspection of the eyes, and
of external orifices of the body; tactile examination of the body and
limbs, and palpation of the groins and abdomen; and in many cases the
microscopical examination of fresh and stained blood-films.

Some of the commoner forms of naturally acquired infection may be
briefly mentioned, without however touching upon the various fleas, lice
and ticks which at times infect the ordinary laboratory animals.

[Illustration: FIG. 165.--Back of inoculation card.]

~The Rabbit~, particularly in captivity, is subject to attacks of Psoric
Acari, and the infection is readily transmitted to rabbits in
neighbouring cages and also to guinea pigs, but not to rats and mice.
One species (_Sarcoptes minor_ var. _cuniculi_) gives rise to the
ordinary mange. The infection first shows itself as thick yellowish
scales and crusts around the nose, mouth and eyes, spreads to the bases
and outer surfaces of the ears (never to the inside of the concha), to
the fore and hind legs and into the groins and around the genitals. The
acari can be readily demonstrated microscopically in scrapings of the
skin, treated with liquor potassae. Another form of scabies (due to
Psoroptes _communis cuniculi_) commences at the bottom of the concha,
which is filled with whitish-yellow masses consisting of dried crusts,
scales, faeces, and dead acari. The base of the ear is hard and swollen,
and lifting the animal by the ears--as is usually done--gives rise to
considerable pain; indeed this symptom may be the one which first
attracts attention to an infection, which causes progressive wasting and
terminates in death. A mixed infection--sarcoptic plus psorotic
acariasis--is sometimes seen.

If it is decided to try and save animals suffering from infection by
these parasites, they must be segregated, the scabs carefully cleaned
from the infected areas and the denuded surfaces washed with 5 per cent.
solution of Potassium persulphate (a few drops being allowed to run into
the concha), or with a preparation containing equal