36 THE HISTORY OF ANIMALS. B. II. 



still. It has large claws, like those of the colius, 1 and it 

 hisses with its voice. 



3. Birds have a mouth, but its construction is peculiar, 

 for they have neither lips nor teeth, but a beak, and 

 neither ears nor nostrils, but only passages for these organs, 

 for the nostrils in the beak, and for the ears in the head. 

 They have two eyes like other animals, without eyelashes ; 

 when heavy with sleep, they close their eyes with the 

 lower eyelid ; and all possess a nictitating membrane, which 

 closes the eye. The owl-like birds also use the upper eye- 

 lid. The same is the nature of the scaly animals, as the 

 tsaurians, and others of this class ; all of them close their 

 eyes with the lower eyelid, but they do not all wink like 

 birds. Again, birds have neither scales nor hair, but 

 feathers ; all the feathers have a stem. 



4. Birds have no tail, but a rump ; in birds with long 

 legs, or palmated feet, this is short, in others it is large. 

 These last, when they fly, keep their legs close to the 

 body, but the others stretch them out behind them. All 

 birds have a tongue, but this differs in various kinds: 

 some have it large, others small. Next after man, some 

 birds articulate words better than any other animals ; this is 

 particularly the case with those with broad tongues. No 

 oviparous animal has an epiglottis on its trachea : but it 

 can close and open the passage, so as to prevent any heavy 

 thing finding its way into the lungs. 



5. Some tribes of birds have spurs; this is never the 

 case with those which have crooked claws. Those with 

 crooked claws are more active in flight ; those which have 

 spurs, are heavier in their make. 



6. Some birds have a crest, mostly formed of erect 

 feathers ; the domestic fowl, alone, is peculiar, for its crest 

 is neither flesh, nor very unlike flesh. 



CHAPTEB IX. 



1. AMONG aquatic animals, there is one class of fish, which 

 embraces many forms, and is separated from other animals, 

 for it has a head, and upper and lower parts, in which last 

 are the stomach and bowels, and a continuous and undivided 

 tail. This is not alike in all. They have neither neck nor 

 limb, nor internal and external testicles, nor mammse, nor 

 1 Perhaps Corvus galgulus. 



