402 THE STRUCTURE AND LIFE OF BIRDS cHApP. 
ones because you have seen them alive and want to 
make out all the details of their plumage, of the 
rarer ones because you, perhaps, have not seen them. 
But, of the two, the common ones are the more im- 
portant ; great rarities may well be dispensed with. 
Museums, therefore, need not be such exterminators 
as private slaughterers who often prize a specimen for 
its rarity and nothing else. 
An ornithologist should understand the art of bird- 
skinning. Bird-stuffers, it is true, are many, and 
there is nearly always one not very far off, but good 
stuffers are rare. It is highly desirable, therefore, to 
be able to make a good skin that can be mounted, if 
you prefer it, afterwards. If he is travelling in an un- 
civilised country, the ornithologist must, of necessity, 
be a bird-skinner, if he wants to bring home any 
specimens. You pick up a good deal in the process 
of skinning besides learning patience. Patience is 
highly necessary, since if you hurry too much or lose 
your temper, there will soon be a rent that may be 
difficult to conceal. You notice, as you go, the bare 
patches or apteria which are so important in classifi- 
cation. You discover the powderdowns of the Heron. 
You get a look at the wing muscles and notice the 
depth of the breast. You appreciate the paper-like 
thinness of the skull. You discover and wonder at 
the extent of the air-cavities under the skin of the 
Gannet. The Starling’s skin, you find, is as tough 
as leather, the Blackbird’s delicate and easily torn. 
You make a point of opening the gizzard to see 
what the bird has been feeding on. The very 
useful art of skinning can be learnt by means of a 
