REPTILES, BATRACHIANS, AND FISHES. 41 
keep fishes, batrachians, and reptiles separate, at least during the 
preliminary stages of conservation. It must always be remembered 
that fishes contain much more water than reptiles, and consequently 
the spirit employed becomes diluted much more rapidly and requires 
to be changed more frequently. In the case of comparatively large 
(2 feet long) and very fleshy fishes, the spirit penetrates very slowly 
into the interior ; and although the specimens may appear to be 
in the best condition externally, the inner layers of muscle above 
and around the vertebral column may be decomposing. It is there- 
fore necessary to make several deep incisions in the muscular part 
of the back and tail in addition to those made along the abdomen. 
Fishes which are loaded with fat, either in the muscles or liver 
or abdominal cavity, should be placed by themselves in very strong 
spirit until the greater portion of fat is extracted ; to accelerate this 
process, the liver should be deeply incised and the masses of fat in 
the abdominal cavity removed. Before being placed in spirit, the 
fish should be washed in water to remove as much as possible of the 
slime with which it is usually coated. 
Fishes which have lost their scales should not be kept ; such as 
lose them easily, like the Clupeidce, should be wrapped in a piece of 
paper or linen before they are put in spirit. 
It occasionally happens in hot climates that, from some cause, the 
collector cannot succeed in preserving his specimens from decomposi- 
tion even with the strongest spirit. In such cases it is advisable to 
add some arsenic or corrosive sublimate to the spirit ; but the traveller 
should inform his correspondents that he has adopted this mode of 
preserving. 
If the colour of the flesh is remarkable, the traveller is recom- 
mended to take a coloured sketch before skinning it. It is generally 
important that coloured drawings made from life should accompany 
a collection ; drawings the originals of which have not been preserved 
at the time have only a subordinate value. 
Dried skins of fish admit only of a superficial and incomplete 
examination, and are easily damaged. This mode of preservation, 
therefore, should only be adopted when it is impossible to obtain a 
sufficient supply of spirit and cases, or when there are no facilities 
for transporting heavy boxes. 
