CIRCLES OF THE SHRIKES AND THRUSHES. Sat 
different perfections, or qualities ; or, in other words, 
the highest degree of organisation. This is the first, 
or typical group. Next in succession comes one closely 
resembling it, but deficient in some few points ; which 
deficiency, however, is made up by a superior degree of 
courage or ferocity, and which, with an organisation 
conformable thereto, leads them to feed upon other 
animals: this is the second in rank, or the sub-typical 
variation. Following this, nature proceeds to another, 
characterised by a large head, great breadth of bill, and 
very short feet ; whose instincts lead them to frequent 
water, or to live in its vicinity. This modification 
always succeeds the sub-typical group, and is followed 
by another, whose chief character is the soft nature of 
its food ; but it is also known by the superior length 
of the bill, and, generally, by the length of its legs. 
The last variation to be found in a true ornithological 
circle is manifested by superiority of bulk, very strong 
legs, glossy plumage, crested head, large tail, short wings, 
gregarious habits, and often a marked predilection for 
the society of man. The voice, also, is peculiarly loud, 
and always discordant. This type of form invariably 
conducts to that which is pre-eminently.typical, and, 
consequently, closes the circle. As this series of vari- 
ations can be traced, more or less, throughout the whole 
animal kingdom, it may, perhaps, be expedient here- 
after to designate each of them by a general name; at 
present, however, they may be called after the primary 
divisions of birds: viz. 1. Insessorial ; 2. Raptorial ; 
3. Natatorial ; 4. Grallatorial or Suctorial ; 5. Rasorial. 
(415.) This definite mode of variation explains the 
nature of the third and last test for the verification of the 
group of shrikes, which we are now considering The 
question, therefore, is this, will the series, as before de- 
tailed, correspond with this series of the variation in all 
other birds? if it will, the group is a natural one; if 
not, there must be some error in the disposition of the 
series. Let us now make the comparison : — 
Z 
