436 COMPARATIVE ZOOLOGY 



The possession of a head distinct from the region behind 

 it is a sign of power. And in proportion as the fore 

 limbs are used independently of the hind limbs, the 

 animal ascends the scale : compare the whale, horse, 

 cat, monkey, and man. 



But shall the fish, never rising above the " monotony 

 of its daily swim," be allowed to outrank the skillful bee ? 

 Shall the brainless, sightless, almost heartless amphioxus, 

 a vertebrate, be allowed to stand nearer to man than the 

 ant ? What is the possession of a backbone to intelli- 

 gence ? No good reason can be given why we might not 

 be just as intelligent beings if we carried, like the insect, 

 our hearts in our backs and our spinal cords in our 

 breasts. So far as its activity is concerned, the brain 

 may be as effective if spread out like a map as packed 

 into its present shape. Even animals of the same type, 

 as vertebrates, can not be ranked according to complex- 

 ity. For while mammals, on the whole, are superior to 

 birds, birds to reptiles, and reptiles to fishes, they are 

 not so in every respect. Man himself is not altogether 

 at the head of creation. We carry about in our bodies 

 embryonic structures. That structural affinity and vital 

 dignity are not always parallel may be seen by compar- 

 ing an Australian aborigine and an Englishman. 175 



Function is the test of worth. Not mere work, how- 

 ever ; for we must consider its quality and scope. An 

 animal may be said to be more perfect in proportion as 

 its relations to the external world are more varied, pre- 

 cise, and fitting. Complexity of organization, variety, 

 and amount of power are secondary to the degree in 

 which the whole organism is adapted to the circum- 

 stances which surround it, and to the work which it has 

 to do. Ascent in the animal scale is not a passage from 

 animals with simple organs to animals with complex 

 organs, but from simple individuals with organs of 



