60 ARISTOTLE. 



which produces deatli. Every species that has 

 wings has also feet. 



In this chapter Aristotle divides animals into 

 such as have bloody and such as have it not. Of 

 the former (the red-blooded) some want feet, others 

 have two of these organs, and others four. Of the 

 latter (the white-blooded) many have more than 

 four feet. Of the swimming-animals, which are 

 destitute of feet, some have fins, which are two or 

 four ; others none. Of the cartilaginous class, those 

 which are flat have no fins, as the skate. Some of 

 them have feet, as the mollusca. Those which have 

 a hard leathery covering swim with their tail. 

 Again, some animals are viviparous, others produce 

 eggs, some worms. Man, the horse, the seal, and 

 other land-animals, bring forth their young alive ; 

 as do the cetacea and sharks. Those which have 

 blow-holes have no gills, as the dolphin and whale. 

 In this department, the observations of the great 

 philosopher are often minute, and generally accurate, 

 although usually too aphoristic and unconnected to 

 be of much use to the student. 



Of flying-animals, some, as the eagle and hawk, 

 have wings ; others, in place of wings, have mem- 

 branes, as the bee and the beetle ; others a leathery 

 expansion, as the bat. Those which have feathered 

 or leathery wings are blooded (red-blooded) ; but 

 those which have membranous wings, as insects, are 

 bloodless (white-blooded). Those which fly with 

 wings or with leathery expansions, either have two 

 feet or none; for, says he, it is reported that there are 

 serpents of this kind in Ethiopia. Of the flying 

 bloodless animals, some have their wings covered 

 by a sheath, as beetles ; others have no covering. 



