334 PRACTICAL AND SCIENTIFIC ZOOLOGY. 
group should receive stronger verification ; thatitshould be 
compared with others of its own order, and finally with 
one of its own rank ; as, for instance, with the family of 
shrikes (Laniade Sw.), and these comparisons are to 
be instituted on precisely the same principles as those 
we have just exemplified. If, therefore, our group will 
bear all these comparisons, and if the same analogical 
results follow, and in the same order, we may then be 
assured that our circle is a true one. And if, to “ make 
assurance doubly sure,” we can extend our comparisons, 
and detect the same analogical resemblances in other 
groups belonging to different classes of animals, we 
not only demonstrate our arrangement of the Merulide 
with almost mathematical certainty, but we pile ac- 
cumulated proofs upon the thoretical assertion that there 
is but one uniform plan of variation throughout nature. 
(410.) The student will now see the worthlessness 
of all assumed circles of affinity which have not been 
put to these necessary tests, and which merely repose 
on the assertion of their inventors. This, in short, has 
been the rock upon which some of the warmest advo- 
cates of this theory have split. While, from the fallacy 
of their circles having been detected, occasion has been 
given to shallow reasoners to throw doubts upon one of 
the greatest truths in natural science ; truths, in fact, 
of which such persons have only a partial knowledge, 
by judging of their value from their mistaken appli- 
cation by zealous but ill-informed advocates. The 
family of Merulide, no doubt, might be arranged 
in two or three circular ways, each of which, if their 
analogical resemblances to other groups are dispensed with, 
would appear to be just as natural as the one here given ; 
for we have tried the experiment. Yet the moment 
these assumed circles are brought up for verification, 
their falsity is at once demonstrated, by their discordance 
with authenticated circles. Hence the student will see 
the reason of our former remark, that false circles of 
affinity can be made with every appearance of being 
natural; and that these will “ pass muster” with all those 
