16 THE BEGINNINGS OF COMPARATIVE ANATOMY 



growth, and reproduction ; they possess only the nutritive 

 soul. Animals possess in addition sensation and the 

 sensitive or perceptive soul "their manner of life differs 

 in their having pleasure in sexual intercourse, in their mode 

 of parturition and rearing their young" (Hist. Aiiiin., viii., 

 trans. Cresswell, p. 195). Man alone has the rational soul in 

 addition to the two lower kinds. 



As it is put in the De Partibns (ii., 10, 656 a , trans. Ogle), 

 " Plants, again, inasmuch as they are without locomotion, 

 present no great variety in their heterogeneous parts. For, 

 where the functions are but few, few also are the organs 

 required to effect them. . . . Animals, however, that not only 

 live but feel, present a greater multiformity of parts, and this 

 diversity is greater in some animals than in others, being 

 most varied in those to whose share has fallen not mere life 

 but life of high degree. Now such an animal is man." 



With the great exception of Aristotle, the philosophers of 

 Greece and Rome made little contribution to morphological 

 theory. Passing mention may be made of the Atomists 

 Leucippus, Democritus, and their great disciple Lucretius, 

 who in his magnificent poem " De Natura Rerum " gave im- 

 passioned expression to the materialistic conception of the 

 universe. But the full effect of materialism upon morphology 

 does not become apparent till the rise of physiology in the 

 1 7th and iSth centuries, and reaches its culmination in the 

 1 9th century. The evolutionary ideas of Lucretius exer- 

 cised no immediate influence upon the development of 

 morphology. 



