314 PRACTICAL AND SCIENTIFIC ZOOLOGY. 
own country, the acquisition of which will mainly de- 
pend upon his own exertions, it is obviously the best 
way to collect them as they occur ; without commencing 
on a regular plan of selection. But if he extends his 
studies, in either of these departments, to foreign pro- 
ductions, most of which are only to be acquired by 
purchase, he will find the beneficial consequences of 
proceeding upon a systematic plan. Should he limit 
his attention, for instance, to ornithology, let him first 
procure types of the great orders of birds, which are 
represented by such common species as a hawk, crow, 
fowl, snipe, and duck. These, for the sake of easy 
examination, should be in skins, that is, stuffed, but 
not set up in position with wires. Let him well study 
the different structures displayed by these specimens, 
and compare their corresponding members, until he is 
well informed on the mode in which these members 
vary. Having thus informed himself on the essential 
or primary characteristics of the first great divisions in 
ornithology, he may proceed a step farther, and procure 
examples of the tribes. The crow is the type of the 
perching order (Jnsessores), the additional tribes of 
which will be represented by a shrike, woodpecker, 
humming-bird, and swallow. These, in like manner, 
should be well examined, and then compared with the 
characters assigned to them in books. A student, in this 
manner, should progressively procure specimens, hus- 
band his resources, and concentrate his attention ; 
while, as his knowledge increases, or as opportunities 
occur, he may successively increase his materials by 
examples of the families, sub-families, and genera ; al- 
ways remembering, that, in point of real utility, although 
frequently not of beauty, the acquisition of a generic 
type is infinitely more desirable than that of a species ; 
unless, indeed, the investigation of the contents of a 
genus is decided upon. What has been said upon orni- 
thology is of equal force when applied either to ento- 
mology or conchology. It will sometimes happen, 
however, that the excessive rarity or the great bulk of 
