126 IV. 10 — iv. II. 



fingers, namely because such projecting parts are weak and there- 

 fore require especial protection. 



(Ch. w.) We have now done with such sanguineous animals as 

 live on land and bring forth their young alive ; ^ and, having 

 dealt with all their main kinds, we may pass on to such sanguineous 

 animals as are oviparous. Of these some ha.ve four feet, while 

 others have none. The latter form a single genus, n9.mely the 

 Serpents ; and why these are apodous has been already explained 

 in the dissertatipn on Animal Progression.^ Irrespective of this, 

 absence of feet, serpents resemble the oviparous quadrupeds in 

 their conformation.^ 



In all these animals there is a head with its component parts ; 

 its presence being determined by the same causes * as obtain in the 

 case of other sanguineous animals ; and in all, with the single ex- 

 ception of the river crocodile, there is a tongue inside the mouth.* 

 In this one exception there would seem to be no actual tongue, 

 but merely a space left vacant for it. The reason is that a croco- 

 dile is in a way a land-animal and a water-animal combined. In 

 its character of land-animal it has a space for a tongue ; but 

 in its character of water-animal it is without the tongue itself. 

 For in fishes, as has already been mentioned, there is either no 

 appearance of a tongue at all, unless the mouth be stretched open 

 very widely indeed ; or, if there be a tongue, it is indistinctly 

 separated from the rest of the mouth.^ The reason for this is 

 that a tongue would be of but little service to such animals, seeing 

 that they are unable to chew their food or to taste it before 

 swallowing, the pleasurable sensations they derive from it being 

 limited to the act of deglutition.''' For it is in their passage down 

 the gullet that solid edibles cause enjoyment, while it is by the 

 tongue that the savour of fluids is perceived. Thus it is during 

 deglutition that the oiliness, the heat, and other such qualifies of 

 food, are recognised ; and in fact the satisfaction from solid 

 edibles and dainties in general is derived almost exclusively 

 from the dilatation of the oesophagus during deglutition.^ This 

 pleasurable sensation, then, belongs to all sanguineous animals, 

 viviparous or not, alike ; but, while the rest have in addition the 

 sensations of taste, tongueless animals have no other satisfaction 

 than it. What has now been said explains why intemperance as 

 regards drinks and savoury fluids does not go hand in hand with 

 intemperance as regards eating and solid relishes.^ 

 691a. 



