10 THE HISTOIIY 01' ANIMALS. [B. I. 



7. Those bloodless animals which have more than four 

 feet, whether furnished with feet or wings, always have more 

 than four organs of locomotion, as the ephemera, which has 

 four feet and four wings ; and in this it not only agrees w r ith 

 its peculiar manner of life, from which also it derives 

 its name, but also that it is winged and four-footed; and 

 all creatures, whether they have four feet or many feet, 

 move in the same direction, for they all move in the long 

 way of their bodies. All other animals have two leading 

 feet, the crab alone has four. 



CHAPTEB VI. 



1. THE following are the principal classes which include other 

 animals birds, fishes, cetacea. All these have red blood. 

 There is another class of animals covered with a shell, and 

 called shell fish, and an anonymous class of soft-shelled 

 animals (malacostraca), which includes carabi, carcini, and 

 astaci ; and another of mollusca, such as teuthis, teuthos, and 

 sepia ; and another class of annulose animals. All these are 

 without blood, and the species with feet have many feet. 

 There are no large classes of other animals ; for there are 

 many forms which are not included under a single form, but 

 either stand alone, having no specific difference, as man, or 

 have specific differences, but the classes are anonymous. 



2. All animals with four feet and no wings have blood. 

 Some of these are viviparous, others oviparous. The vivi- 

 parous are not all covered with hair, but the oviparous have 

 scales. The scale of a reptile is similar in situation to the 

 scale of a fish. The class of serpents, sanguineous land ani- 

 mals, is naturally without feet. Though some have feet, this 

 class is also covered with scales. All serpents, except the 

 viper, are oviparous. The viper alone is viviparous, so that 

 not all viviparous animals have hair ; for some fishes also are 

 viviparous. All animals, however, that have hair are vivi- 

 parous ; for we may consider the prickles of the hedgehog 

 and porcupine as analogous to the hair of animals ; for they 

 answer the purpose of hair, and not, as in marine animals 

 that are so covered, of feet. 1 



3. There are also many classes of viviparous quadrupeds, 



1 The Echinidffi. 



