80 EVOLUTION OF MIND 



Taking them one by one in the descending series, the 

 orders of each class of the Mammalia that manifest the 

 highest degree of intelligence are the 



1. Bimana higher man only, however. 



2. Quadrumana, especially the larger anthropoid apes. 



3. Carnivora, including especially the dog and cat. 



4. Proboscidia, especially the elephant. 



5. Ungulata, especially the horse, mule, and ass. 



6. Rodentia, especially the beaver and rat. 



The other orders of the (7) Monotremata, (8) Marsupialia, 

 (9) Edentata, (10) Sirenia, (11) Cetacea, (12) Hyracoidea, (13) 

 Cheiroptera, and (14) Insectivora are not distinguished for 

 intelligence, so far as we yet know, though some of them 

 for instance, the two last rank in the mere zoological scale 

 above all animals save the Quadrumana and Bimana. The 

 Insectivora include moles, shrew mice, and hedgehogs ; while 

 the Cheiroptera consist of the bats none of them com- 

 parable, as regards intelligence, with the dog, elephant, 

 or other animals that rank lower in the artificial systems of 

 the zoological classificator. 



Hitherto we have considered the psychical characters of 

 subkingdoms, classes, orders, genera, and species. But 

 another perhaps more convenient and interesting mode of 

 studying comparative psychology is to take some one mental 

 faculty or aptitude and trace its progress either downwards 

 or upwards. For instance, we may take up the moral sense 

 as it is developed in civilised man, and trace downwards its 

 modifications, until it disappears in lower or savage man, in 

 the Quadrumana, the dog, and other animals. Or we can 

 take memory, volition, emotion, thought, and trace their 

 dawnings in plants and the lowest animals up to their 

 highest developments in cultured man. Both plans should 

 be followed by the student; both have been followed through- 

 out this work, which contains abundance of data for a pre- 

 liminary study at least of such a kind. 



For instance, let us take up obedience to a human master's 

 orders, with all that it implies such as the understanding 

 of one or more forms of man's language. We find this oc- 

 curing as low down as among bees (' Percy Anecdotes ') and 



