{2 AMPHIBOLZ—ANATOMY 
AMPHIBOLA, a group of birds so called by Nitzsch in 1829 
(Observationes de Avium Carotide communi, p. 16) comprising the 
genera, as then understood, Musophaga (TouRAco), Colius (MOUSE- 
BIRD), and Opisthocomus (HOACTZIN); but by no means to be con- 
founded with the 
AMPHIBOLL, one of Illiger’s groups, defined in 1811 (Prodromus 
Systematis Mammalium et Avium, p. 203), and composed of the 
genera Crotophaga, Scythrops, Bucco, Cuculus and Centropus—the 
third of which is treated of under the titles of BARBET and PUFF- 
BIRD, while the rest will be found under those of ANI, CHANNEL- 
BILL, and CuckKow. 
AMPHIBOLIC is a toe which can be reversed at will either 
backwards or forwards. The outer or fourth toe is amphibolic, 
and can be turned backwards in Pandion, the Striges, Musophagide, 
Leptosomatide, and Coliide. This feature, when retained, forms 
the true zygodactyle foot. The MouSE-BIRDS can turn the first toe 
forwards, being thus enabled temporarily to assume the condition 
of some of the SwIrTs, or that of zygodactyle birds. Reversion of 
the second toe backwards has produced the pseudo-zygodactyle or 
heterodactyle foot of the TRoGONS (see SKELETON). 
AMPHIMORPH A, the name given by Prof. Huxley (Proc. 
Zool. Soc. 1867, p. 460) to his second group of DESMOGNATHA, 
which consists of the genus Phenicopterus (FLAMINGO), as being 
“so completely intermediate between the Anserine birds on the 
one side, and the Storks and Herons on the other, that it can be 
ranged with neither of these groups, but must stand as the type 
of a division by itself.” 
ANATOMY (dvaropia, dissection) is that branch of zoology 
which deals with the description of the organic structure of animals ; 
a branch of this zootomy is Histology, the knowledge of the composi- 
tion of the tissues of the various organs. The object of Comparative 
Anatomy is the explanation of the features exhibited by the animal 
organization. 'The comparative method examines numbers of differ- 
ent animals (or plants) with reference to the anatomical structure 
of their various organs, putting similar conditions together, and 
separating or excluding those which are dissimilar. By observing 
in such organs their size, number, shape, structure, relative posi- 
tion to other organs, and their development, we ultimately acquire 
a knowledge of such a series of conditions or features, exhibited 
by one and the same organ, which in their extremes may appear 
totally different, but are connected with each other by numerous 
intermediate stages. By proceeding in such a way, we are, for 
instance, enabled to understand the ankle-joint of Birds, by com- 
paring the bones of their hind limbs with those of Mammals 
