s A' '/'.•/ TAJA'
or so and then separated. By this maneuver a subcuta-
neous pocket is formed, into which the tissue is easily
forced. The opening should not be large enough to re-
quire subsequent stitching.
vSinall animals, like rabbits and guinea-pigs, can be held
in tlie hand, as a rule. Rabbit-holders of various forms
can be obtained from dealers. Dogs, oats, sheep, and goats
can be tied and held in I toughs, A convenient form of
mouse-holder, invented by Kitasato, is shown in Pig. 42.
In all these experiments one must remember that the
amount of material introduced into the animal must be
in proportion to its si/.e, and that injection-experiments
upon mice generally are so crude and destructive as to
warrant the comparison drawn by Frankel, that to inject
a few minims of liquid into the pleura! cavity of a mouse
is u much the same as if one would inject through a fire-
hose three or four quarts of some liquid into the respira-
tory organs of a man.11
The blood of animals, when it is necessary to experi-
ment with it, is best secured from
a large vein, generally the jugu-
lar, From small animals, such as
guinea-pigs, it may be secured by
introducing a small eannula into
the carotid artery.
Our observations of animals by
no means cease with their death,
Indeed, he cannot be a bacteriol-
ogist \vho is not already a good
pathologist, and expert in the recog-
nition of diseased organs.
When an autopsy is to be made
upon a small animal, it is best to
wash it for a few moments in a
disinfecting solution, to kill the
germs present upon the hair and the skin, as well as to
moisten the hair and enable it to be kept, out of the