THE SCALE OF BEINGS 15 



grew) and pain (when they lost their leaves), animals had 

 in addition " Nous." In Empedocles' theory of evolution, the 

 vegetable world preceded the animal. Plato, in the Timaeus, 

 describes the whole organic world as being formed by 

 degradation from man, who is created first. Man sinks first 

 into woman, then into brute form, traversing all the stages 

 from the higher to the lower animals, and becoming finally 

 a plant. This is a reversal of the more usual notion, but 

 the idea of gradation is equally present. 



Aristotle seems not to have believed in any transforma- 

 tion of species, but he saw that Nature passes gradually from 

 inanimate to animate things without a clear dividing line. 

 " The race of plants succeeds immediately that of inanimate 

 objects" (Cresswell, loc. cit., p. 94). Within the organic 

 realm the passage from plants to animals is gradual. Some 

 creatures, for example, the sea-anemones and sponges, might 

 belong to either class. 



Aristotle recognised also a natural series among the 

 groups of animals, a series of increasing complexity of 

 structure. He begins his study of structure with man, who 

 is the most intricate, and then takes up in turn viviparous 

 and oviparous quadrupeds, then birds, then fishes. After the 

 Sanguinea he considers the Exsanguinea, and of the latter 

 first the most highly organised, the Cephalopods, and last the 

 simplest, the lower members of his class of the Testacea. In 

 treating of generation (in Hist. Aniinaliiiin, v.) he reverses 

 this order. In the De Generatione (Book ii., r) there is given 

 another serial arrangement of animals, this time in relation 

 to their manner of reproduction. There is a gradation, he 

 says, of the following kind : 



1. Internally viviparous Sanguinea "| producing a perfect 



2. Externally viviparous Sanguinea/ animal. 



3. Oviparous Sanguinea producing a perfect egg. 



4. Animals producing an imperfect egg (one which 



increases in size after being laid). 



5. Insects, producing a scolex (or grub). 



In Aristotle's view the gradation of organic forms is the 

 consequence, not the cause, of the gradation observable in 

 their activities. Plants have no work to do beside nutrition, 



