244 Notes, iv. 12. 



and without epiglottis ; a common orifice for excrement and for generative products ; 

 and lastly in closing the eye, with some few exceptions, with the lower lid (ii. 13, l), 

 the lids being without lashes excepting in the ostrich (ii. 14, i). 



On the other hand, they differ from reptiles and from all other sanguineous animals in 

 having feathers in place of hairs or scales, a beak in place of lips and teeth, and wings in 

 place of arms or fore-legs. The "ischium" is extremely long (Note 27) ; the legs turn 

 their convexity backwards (Note 10 ; De Inc. 15 ; H. A. ii. I, 13) ; the toes, excepting in 

 the ostrich (iv. 14, Note 4), are four in number (Note 30). The bones are brittle (ii. 9, 

 Note 6), and the breast-bone sharp-edged and thickly covered with flesh, especially in 

 birds of rapid flight {^De Inc. 10, 9). The testes are internal. There is no bladder, though 

 there are flat kidney-like organs (iii. 9, Notes i and 2). There is invariably a tongue 

 {H. A. ii. 12, 9) ; there are no teeth, their office being discharged by variable arrange- 

 ments of the stomach and intestines (iii. 14, 9-10) ; there is always a gall-bladder 

 (^H. A. ii, 15, 12) ; and usually there are one or two ca;cal appendages to the gut low 

 down {H. A. ii. 17, 34). The ears and nostrils are represented by simple orifices. 

 The eyes are provided with a nictitating membrane (ii. 13, Note 2). 



A. makes no exhaustive division of birds. The following groups are, however, distinctly 

 recognised by him. 



(rt) Birds of prey, with talons and hooked beak, fleshy breast and stout thighs {H. A. 

 ii. 12, 3), small bodies, powerful wings, abundant feathers, keen sight {De Inc. 

 10, 8-10). These are clearly our Raptores ; with which, however, A. also 

 classes the parrot (ii. 17, Note 3). 

 {b) Heavy-bodied birds, ill-suited for flight, of terrestrial habits, fond of dusting 

 themselves, often with spurs (cf. ii. 13, Note i). These answer generally to 

 our Gallinacese, 

 {c) Dovelike birds, laying two white eggs, etc. ; clearly Columbid?e. 

 {d) Swimming birds, wholly or partially webfooted (Note 8), with long neck, short 



legs and tail ; our Natatores. 

 (e) Marsh birds, with long legs and neck, the front toes elongated, the hind toe short ; 



our Grallatores. 

 (_/^ The ostrich, which stands alone (iv, 14% represents our Ratitse or Cursores. 



These are the only groups distinctly recognised by Aristotle ; for such 

 terms as "insect-eaters," "grub-eaters," "thistle-eaters," etc, are hardly meant 

 to represent definite subdivisions. 



2. The class A ves is remarkably homogeneous. "The structural modifications which 

 they present are of comparatively little importance " {Huxley), 



3. Cf. iv. 6, Note 6. 



4. Cf. ii. 16, Note 5. 

 6. Cf. iv. 5, Note 8. 



6. Not actually bony, but resembling bone in being hard. Cf. ii. 9. 16. 



7. Cf. iii. 3, Note 3, and iv. 10, Note 7. 



8. The birds alluded to are the Grebes, the Phalaropes, the Coots, in which the toes 

 are bordered with broad membranous lobes, which led Temminck to arrange them in 

 one order to which he gave the name of Pinnatipedes. A. describes this arrangement 

 in more distinct language farther on in the chapter. The word which he uses here 

 to describe the toes, and which I have rendered "flattened and expanded into lobes," 

 is literally " snubnosed." Liddell and Scott, referring to this passage, interpret the 

 term as "with turned-up feet, like some waders." But clearly it is not the tumed-up 

 character of a snubnose, but its flat and broad aspect which forms the ground of the 



