INTRODUCTION. xxxvii 



larvae ; they are also taught to distinguish between friends and foes." When an ant's 

 nest is attacked by foreign ants, the young ones never join in the fight, but confine 

 themselves to removing the pupte; and Forel has by experiment proved that the 

 knowledge of hereditary enemies is not wholly instinctive in ants. 



Moreover, besides carrying on the complicated duties of the formicary, ants add 

 to their labors by keeping in their nests milch cows, as the Aphides substantially are ; 

 they also carry on slave-catching wars, and keep slaves generation after generation, 

 with the same results of enfeebling and deteriorating the body and mind of the mas- 

 ters, as has been experienced in human life. Ants also keep pets, and, to go to another 

 extreme, carry on wars of conquest, rapine, and plunder, A few human races are said 

 not to bury their dead : if this be so they are inferior to ants, whose care in disposing 

 of the bodies of their dead has attracted the notice of Sir John Lubbock ; and that 

 they actually in some cases bury their dead was claimed by Pliny, and substantiated 

 by recent observers, according to Romanes. And then we have the leaf-cutting ants, 

 harvesting ants, honey-making ants, military ants, ants which bridge streams, dig wells, 

 and tunnel under broad rivers. 



Wasps and bees can see much better than ants ; indeed, they are far more depen- 

 dent than the latter on the power of perceiving flowers, they also have a highly 

 developed sense of direction, powers of communication, while the combined instinc- 

 tive and reasoning powers they exhibit in making their nests, and in providing for or 

 caring for their young are proverbial. Whether the instinct of building hexagonal 

 cells is purely automatic or not has been disputed, but now it is conceded by Darwin, 

 Romanes, and others that the process is not a purely mechanical one, but is " constantly 

 under the control of intelligent purpose ; " in other words, the worker bee knows what 

 it is about, is a conscious agent. 



Spiders also, though their nervous system is much less complicated than that of 

 ants and bees, as well as insects in general, being built upon a different plan, 

 show the most astonishing intellectual powers, particularly in spinning their webs ; 

 while as examples of special instincts the result of reasoning processes, at least in the 

 beginning, are the acts of the water spiders, and especially the trap-door spiders. 



Spiders also, like ants and bees, are able to distinguish between persons, approach- 

 ing those they know to be friendly, and shunning strangers. It is well known that 

 spiders can be tamed, and there are well-authenticated anecdotes testifying to the 

 high degree of intelligence of these creatures. 



Passing now to the branch of vertebrates, we do not find a sudden rise in the 

 intellectual scale from bees to fishes, but that in reality fishes and reptiles are not so 

 highly endowed mentally as the most highly organized insects. As Romanes truly 

 says : " Neither in its instincts nor in general intelligence can any fish be compared 

 with an ant or bee, — a fact which shows how slightly a i^sychological classification of 

 animals depends upon zoological aifinity, or even morphological organization." 

 Fishes, he states, " display emotions of fear, pugnacity ; social, sexual, and parental 

 feelings; anger, jealousy, play, and curiosity. So far, the class of emotions is the 

 same as that with which we have met in ants, and corresponds with that which is dis- 

 tinctive of the psychology of a child about four months old." 



Of batrachians, frogs and toads have more or less definite ideas of locality, while 

 they will learn to recognize the human voice and come when called. The general 

 intelligence of reptiles is higher than that of fishes and batrachians, but low compared 

 •^vith that of birds. Snakes and tortoises are said to be able to distinguish persons ; 



