ARISTOTLE 



Form, p. 726;. The co-ordinates to which he refers 

 are those of the Cartesian method, on which is based 

 the theory of Transformations. By means of them 

 it is possible to exhibit, say, the cannon-bones of the 

 ox, the sheep, and the giraffe as strictly proportionate 

 and successive deformations of one and the same form. 

 These deformations can be either simple elongations, 

 as in the instance just cited, or they may occur 

 according to an oblique or a radial system of co- 

 ordinates, etc." In this way, differences of " excess 

 and defect " are reduced to the terminology of 

 mathematics ; and it is especially interesting to 

 notice this, as the phrase " excess and defect " itself 

 had, in the Greek of Aristotle's time, a mathematical 

 connexion. With it may be compared the well- 

 known Platonic phrase, " the great and small." But 

 this is not the place to enlarge upon such topics.^ 

 ciassifica- To rctum to Aristotle's classification. We find 

 ^mrts! t^^^^ ^^ implements his preliminary outline in the 

 following way : 



I. First, he treats of the parts which are found in 

 many different groups of animals, and also those 

 which are to be considered counterparts of each 

 other in different groups. This corresponds to 

 A (1) above. 



II. As he proceeds 'vvith this, he comes to the 

 Viscera, which occur only in blooded animals." 

 This provides a convenient point for embarking 

 upon his second main division — corresponding 



* For details see D'Arcy Thompson, op. cit. eh. xvii. 



* The reader is referred to A. E. Taylor, " Forms and 

 Numbers," in Mind, xxxv. 419 foil. ; xxxvi. 12 foil. ; D'Arcy 

 Thompson, " Excess and Defect," in Mind, xxxviii. 43 foil. 



•^ By " viscera " Ar. means the blood-like ones only. 

 20 



