2 THE HISTOBY OF ANIMALS [ Bl If 



sometimes in number more or less, or in size greater and 

 smaller, or in any quality which can be included in excess 

 or defect. For some animals have a soft skin, in others the 

 skin is shelly ; some have a long bill, as cranes, others a 

 short one ; some have many feathers, others very few ; some 

 also have parts which are wanting in others, for some species 

 have spurs, others have none ; some have a crest, others have 

 not. But, so to say, their principal parts and those which 

 form the bulk of their body, are either the same, or vary 

 only in their opposites, and in excess and defect. 



4. By excess and defect I mean the greater and the less. 

 But some animals agree with each other in their parts neither 

 in form, nor in excess and defect, but have only an analogous 

 likeness, such as a bone bears to a spine, a nail to a hoof, 

 a hand to a crab s claw, the scale of a fish to the feather of 

 a bird, for that which is a feather in the birds is a scale in 

 the fish. With regard then to the parts which each class 

 of animal possesses, they agree and differ in this manner, 

 and also in the position of the parts. For many animals 

 have the same parts, but not in the same position, as the 

 mammae which are either pectoral or abdominal. But of the 

 simple parts some are soft and moist, others hard and dry. 



5. The soft parts are either entirely so, or so long as they 

 are in a natural condition, as blood, serum, fat, tallow, mar 

 row, semen, gall, milk (in those animals which give milk), 

 flesh, and other analogous parts of the body. In another 

 manner also the excretions of the body belong to this class, 

 as phlegm, and the excrements of the abdomen and bladder ; 

 the hard and dry parts are sinew, skin, vein, hair, bone, car 

 tilage, nail, horn, for that part bears the same name, and on 

 the whole is called horn, and the other parts of the body 

 which are analogous to these. 



6. Animals also differ in their manner of life, in their ac 

 tions and dispositions, and in their parts. We will first of 

 all speak generally of these differences, and afterwards con 

 sider each species separately. The following are the points 

 in which they vary in manner of life, in their actions and 

 dispositions. Some animals are aquatic, others live on the 

 land ; and the aquatic may again be divided into two classes, 

 for some entirely exist and procure their food in the water, 

 and take in and give out water, and cannot live without it j 



