132 A SCIENTIFIC APPRECIATION [oh. yl 
claws, and so forth. Some went so far as to take 
the tongue as their guide, but it proved, as the late 
Prof. Alfred Newton said, a very unruly member 
for the classifier! All these characters are of 
zoological interest, but they are superficial adapta¬ 
tions to similarities of habit, and are of no service in 
revealing the deep-seated structural affinities which 
a natural classification should reflect. Thus it is 
certain that swifts are not nearly related to 
swallows, nor owls to eagles and hawks. 
Prof. Alfred Newton points out that in Sir 
Richard Owen's celebrated article “Aves,” in 
Todd’s Cyclopaedia of Anatomy and Physiology, which 
appeared the year before the first volume of Mac- 
Gillivray’s British Birds , the distinguished zoologist 
was content to adopt, as he tells us, a classification 
proposed by Kirby, which was practically that of 
Linnaeus, improved by Cuvier, with an additional 
modification of Illiger’s—“all these three authors 
having totally ignored any but external characters.” 
What then did MacGillivray do ? He insisted 
on getting below superficialities to the internal 
architecture, devoting particular attention to the 
alimentary system. This was a turning point in the 
history of British ornithology, and it may be of 
interest still to quote some of the terms of Mac¬ 
Gillivray’s thesis:— 
“ Some ingenious writers have attempted to 
show that a knowledge of the internal structure of 
animals is not essential to the zoologist, who, it is 
said, may get on remarkably well, and form the 
