53 
Where many skins are handled, professional trappers usually keep 
drying-boards or frames on hand. Wire stretching-frames are inexpensive, 
may be easily made or purchased, and may quickly be adjusted to any 
size of pelt and allow space for a circulation of air between the sides 
of the pelt, thus hastening the curing process. Another great advantage 
of the wire stretcher is that the springy sides need only to be compressed 
and the dried skin slips off without sticking or tearing the hide or the fur. 
The average collector, who only puts up an occasional cased skin, will 
usually find it less trouble to improve a stretcher from a piece of packing 
box, shingle, split cedar shake, or bent willow saplings, than to keep 
on hand elaborate equipment that is seldom used. 
An adaptation of the method of “casing" skins used by commercial 
trappers as described by the writer in the first edition of this work (1932, 
pages 45-48) , was described as a practical means of getting mammal skins 
from persons who had neither the time nor the inclination to “make" the 
conventional type of “scientific or study skin." Such skins are as useful as 
any other “make" for the purposes of mounting, and to all intents and 
purposes known to the writer are perfectly suitable for study purposes. 
If the owner insists on having his skins uniformly made it is quite feasible 
to relax the cased skin and make it up in the orthodox style, an operation 
which has been commonly done in the past. If pasteboard is used for a 
stretcher it may be left inside the skin and the necessary data written on the 
bottom (Figure 12). If badly soiled, the stretcher may be replaced by a 
clean one. It has also been suggested that if a permanent mounting card 
be cut from transparent sheet celluloid to replace the original cardboard 
stretcher the hind feet and tail may have the under surfaces examined 
without removing the stitches binding them down. 
Mr. Charles Elton, Director, Bureau of Animal Population, University 
Museum, Oxford, England, has been carrying on extensive experiments in 
preparation and storage of flat or cased skins, and referring to the method 
described by the writer in first edition of this bulletin (1932), writes as 
follows (1938, pages 244-245): 
“The following extensions of this technique have been made. Suppose one has 
cased a mouse skin: instead of tying a label onto the animal, one leaves sufficient 
of the stretcher card behind the hind legs to allow the data to be written upon it, 
and the hind legs and tail to be secured to the card with thread. The base of 
the card is cut to a standard width that is considerably wider than the mouse, 
the width used for small mammals, such as mice, is 4 inches. The whole mounted 
specimen with its card is put inside a cellophane envelope, 4*25 x 11 inches, open 
at both ends so that the mouse can always be slid in and out with the grain 
of the fur. The resulting product is a flat specimen of which both sides can be 
examined without removal from its envelope. It can be removed in an instant if 
desired, the hind legs and tail are safe from injury, and the records are securely 
attached to the skin and are visible at a glance. The mounted specimens can 
then be stored in cabinet drawers or boxes, and classified with guide cards or 
individually distinguished. This system has especial value where large numbers 
of skins are being collected for ecological or genetic study, but it may prove also 
to be of use to the museum expert, provided he does not insist on having round skins 
for comparative work. The cased skin is inevitably wider than the animal, but 
this point appears less serious when it is realized that reliable measurements 
can in any case only be made on the body itself. . . . Casing skins is at least 
as speedy as any other method, but there is a potential waste of time in cutting 
cards to the exact size required in each instance. This difficulty is overcome 
by having a set of flat metal gauges by whose aid the right size of card can 
quickly be found. Each gauge has a line drawn down the centre marked at 
