12 AMPHIBOLY.— ANATOMY 



AMPHIBOL^^, a group of birds so called by Nitzsch in 1829 

 (Obsej-vationes de Avium Carotids 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 



AMPHIBOLI, one of Illiger's groups, defined in 1811 (Prodromus 

 Systeniatis Mammalium ei Avium, p. 203), and composed of the 

 genera Crotophaga, Scyfhrops, 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 CUCKOW. 



AMPHIBOLIC is a toe which can be reversed at will either 

 backwards or forwards. The outer or fourth toe is amjDhibolic, 

 and can be turned backwards in Pandion, the Striges, Musophagidae, 

 Leptosomatidae, and Coliidie. 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 Swifts, or that of zygodactyle birds. Reversion of 

 the second toe backwards has produced the pseudo- zygodactyle or 

 heterodactyle foot of the Trogons (see Skeleton). 



AMPHIMOBPH.E, the name given by Prof. Huxley {Proc. 

 Zool. Soc. 1867, p. 460) to his second group of Desmognath^, 

 which consists of the genus Phcenicopterus (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 (draro/xta, 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 knoAvledge of the composi- 

 tion of the tissues of the various organs. The object of Comparative 

 Anatomy is the explanation of the features exhiliited 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 



