THE HISTORY OF ANATOMICAL SCIENCE 279 



become the standard of comparison, or, in other 

 words, the ' type ' to which all other kinds of 

 animal structure were to be referred. The organs 

 of animals were interpreted by the analogy of 

 those of man ; the terminology of human struc- 

 ture was extended to the structure of animals in 

 general. 



Thus the anatomy of the whole of the rest of 

 the animal world came to be regarded as a sort 

 of annexe of human anatomy ; it acquired the 

 name of ' comparative anatomy/ and the concep- 

 tion of the relations of man to the rest of the living 

 world was completely falsified. Man, regarded 

 merely as an animal, was held to be the most 

 perfect of all the works of Nature, below which 

 all the rest could be arranged in a graduated 

 series of forms to the lowest animals ; from thence, 

 the descending steps were traced through the 

 vegetable world to the lowest plants ; and through 

 the definitely formed to the apparently indefinite 

 mineral constituents of the globe. Hence arose 

 the conception of une echelle des etres, a ladder 

 between stones and men, the rungs of which are 

 the species or kinds of living things. 



But gradation implies a certain community 

 between the grades. Degrees of colour are 

 shades of the same colour, or mixtures in which 

 the same colours exist in varying proportions ; 

 gradations of form imply similarities of form 

 between the successive steps of the gradation. 



