THE 
AMERICAN NATURALIST. 
VoL. xvi.—OCTOBER, 1883.—No. 10.. 
MAN’S PLACE IN NATURE, 
BY W. N. LOCKINGTON. 
PECIALIZATION is not in itself any proof of advance, yet 
7 both in the domain of mind and that of organic life the term 
is constantly used as though it carried with it the idea of pro- 
gress, instead of, as is the fact, a mingling of advance with retro- 
gression, the upward or downward tendency of which can only 
be determined by a careful comparison of all the factors. 
In all evolution, organic or super-organic, specialization com- 
Mences at the bottom of the scale, anda higher grade is only 
attained by a longer continuance in a generalized condition be- 
fore specialization—a continuance during which, not some special 
part but the entire organism becomes capable of wider activities. 
As the upward development proceeds, branches break off, become 
Specialized, and perfect or complete themselves, that is, become 
incapacitated for further development. The real line of advance 
is not to be sought for in the specialized offshoot, but in the grow- 
ing stem from which it parted. 
To give examples from the Vertebrata; it is not the highly 
Specialized teleostean fish, such as the perch, that is in the line of 
advance, but the more generalized ganoids and Dipnoi through 
which the upward line runs on into the Batrachia; neither is it 
the highly specialized flying pterodactyl that is in the line of ad- 
vance from reptile to bird or mammal; nor can the line of mam- 
malian descent be traced through the birds, in which, high though 
the type is, specialization of some parts, accompanied by atrophy 
of others, has resulted in organic completeness at a level lower 
than that which has been reached by the summit of the mamma- 
lian stem. 
The highest specialization is that based upon perfection of the 
VOL. Xvir.—no, x. 67 
