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 itres, a ladder 
between stones and men, the rungs of which are 
the species or kinds of living things. 
But gradation implies a certain community 
betw'een 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. 
