20 
Cotton thread Nos. 8, 25, 36, 40, 50, and 60 should be kept, as well as 
linen thread Nos. 40, 50, and 60. Two or three spools will be sufficient for 
sewing up several hundred small specimens, but it is well to have a few 
extra spools of the larger sizes for tying labels or wrapping up skeletons. 
Strong linen thread, No. 40, is preferable for tying small paper labels. A 
smaller size would perhaps have sufficient strength, but the thread is more 
apt to cut through the paper. 
Wire 
Wire is not much needed by the collector of bird skins, but a small 
amount of Nos. 11, 16, and 22 should be available for necks of swans, 
herons, cranes, and other large birds that have long, curved necks. A spool 
of fine tinned wire is needed for splicing an occasional broken leg or beak 
of a small bird, and for wiring loose tail feathers. 
The mammal collector will need a larger amount of wire of assorted 
sizes. If “study skins” are to be made up, wire of sizes Nos. 16, 18, 20, 
22, 24, and 26 will be needed for wiring the tails. For general use, shrews 
and small mice require 24 gauge American or English; mice and rats 22 
gauge (the size most needed); rats and squirrels 20 gauge; medium-sized 
squirrels 18 gauge American; large squirrels 16 gauge American or 18 
gauge English; rabbit legs, 12 gauge American or 14 gauge English. 
Mammals needing wire heavier than No. 16 are seldom made up in the field, 
and only the smallest mammals require a wire as small as No. 26. By far 
the greatest number of skins will be prepared with Nos. 18, 20, and 22. 
The ideal wire should be non-corrodible. Galvanized or tinned iron ware, 
brass wire, and copper wire have been much used. Brass wire and copper 
wire are generally too flexible to be used in the smaller sizes, and Monel- 
metal wire has been found to be the best for general purposes. Monel- 
metal is a bright, whitish alloy (nickel 75 per cent, copper 23*5 per cent, 
and iron 1*5 per cent) that does not corrode in ordinary liquids (water, 
brine, formalin, alcohol, etc.). Plain, soft, annealed iron wire may, however, 
be used without much danger if care is taken to wrap it thoroughly with 
cotton. An unwuapped iron ware put inside of a moist tail, is almost sure 
to rust and discolour the skin. For the sake of safety, iron wire may be 
coated with shellac, wdiich dries quickly, but the wure should be w r rapped 
in any event. Spring wire may be annealed by heating it red-hot and 
allowing it to cool slowly. 
Some judgment must be used as to the size of wire employed, but in 
general the wire should be heavy enough to give reasonable stiffness to the 
tail, and small enough to penetrate to the extreme tip of the tail sheath 
without pulling off the end of the tail. In practice it is often advisable to 
use a wire slightly larger than the tip of the tail, particularly with long, 
slender tails like those of jumping mice and pocket mice, and to sharpen 
the tip of the wire wuth a file, slightly roughening the tip so that the cotton 
wrapping will not slip off. 
With small mammals, the tail wure is usually the only wire used. If 
the leg bones are cut off short, or broken, it may be advisable to put a 
wire on each leg. In rabbits, and similarly long-legged animals, the legs 
need stiffening and considerable large wire is needed, so that 5 pounds of 
large wire will not last very long. A pound of No. 22 wire will serve for 
a hundred or more small mammals. 
