252 ELEMENTS OF OENITHOLOGT. 



and sexual characters." Sometimes when a " class " contains 

 very many or very different " orders," the latter may be arranged 

 in sets, each of which is termed a subclass. Similarly when 

 there are many families in an order, such families may be 

 grouped in suborders ; and sometimes the suborders have to be 

 further divided into sections so that the families which compose 

 it may be arranged in different sets. 



When also there are many genera in a family, such family is 

 divided into subfamilies to receive different groups of such 

 genera ; and very many " subfamilies " are found in Ornitho- 

 logy- 



As we said in our introductory Chapter ^, all Birds taken 

 together form one class of Vertebrate, or back-boned. Animals, 

 and all Vertebrate animals taken together constitute a primary 

 divison of the Animal Kingdom called the Subkingdom. Verte- 

 brata. The class of Birds — the class Aves — has been at different 

 periods divided in various ways. Divisions — more physiological 

 than morphological — were instituted by both Linnseus and 

 Cuvier, on the lines of those differences of habit, and to a 

 certain extent, of structure, which were referred to when we 

 spoke ^ of the Scratchers and Cooers and Climbers, and Waders 

 and Swimmers, and birds of llaptorial habit. 



By Linnaeus, Birds were arranged ^ in six orders : — 1. Acci- 

 pitres (Birds of Prey). 2. Picoe (Humming-birds, Hoopoes, 

 Crows, Birds of Paradise, Toucans, Trogons, Parrots, Wood- 

 peckers, Wrynecks, Cuckoos, Barbets, Hornbills, Kingfishers, 

 Flycatchers, Honey-eaters, and Todies). 3. Anseres (Aquatic 

 Birds). 4. G'/'aZte (Waders, Ostrich, &c.). 5. G^aZKnoe (Gallina- 

 ceous Birds). And 6. Passeres (all the smaller Birds). 



Cuvier also arranged Birds in six almost similar orders, as 

 follows : — 1. Accipitres (Birds of Prey). 2. Passerince (including, 

 with LinnsBus's Passeres, also the Crows, Birds of Paradise, 

 Humming-birds, Hoopoes, Todies, and Hornbills). 3. Scansorice 

 (the rest of Linnaeus's " Picae "). 4. Oallinacem (Gallinaceous 

 Birds). 5. Orallatorice (Waders, the Ostrich, &c.). 6. Palmi- 

 pedes (Aquatic Birds). 



He also subdivided his Passerinse into sections according to 

 the shape of the beak in the way previously stated *. 



These classifications were long ago felt to be unsatisfactory, 



' See ante, p. 1. ^ See ante, pp. 67 & 131. 



' In the ' Systema Naturae,' 1766, tomus i. 

 * See ante, p. 132. 



