590 THE POPULAR SCIENCE MONTHLY. 



Dr. Kane tells us that one of the Newfoundland dogs which spent 

 two arctic winters with him was so oppressed by the darkness and 

 solitude of the long night, and so reduced in strength by hardship 

 and cold, that it at last became insane, and manifested all the symp- 

 toms which were observed in some of the human beings of the party 

 who were affected in the same way by the same causes. 



Many animals, poultry for instance, have special cries for special 

 purposes : an alarm-cry to indicate danger ; a call to announce the dis- 

 covery of a supply of food ; a maternal " cluck " to keep the brood of 

 chicks together; and several other cries, each of which has a meaning. 

 These cries are undoubtedly produced and understood by the fowls 

 instinctively, but the process by which man learns to recognize them 

 and to understand their meaning is purely intellectual. The farmer's 

 dog learns to distinguish and understand them as well as the farmer 

 himself, and knows when he may be unconcerned, and when he is to 

 go to their defense ; and there is not the slightest reason to doubt 

 that he acquires his knowledge, as man does, by a process of obser- 

 vation, memory, and thought. Instances of intelligence among the 

 higher mammalia could, of course, be indefinitely multiplied, but it 

 does not seem necessary to dwell upon the subject here. I will, how- 

 ever, give a few examples of what seems to be intelligence among 

 the lower animals. I think it was Lubbock who observed a spider 

 which wished to raise a captured wasp to a more elevated portion of 

 the web. Finding it too heavy, it stopped its efforts and gnawed off 

 two of the wings, and then made a second attempt. As it was still 

 too heavy, it lightened it still furtlier, and again tested it, and re- 

 peated the process until it had reduced its load to a manageable size. 

 I am unable to give the authority for the following, but think the 

 account was published in Nature some years since: A gentleman 

 found a small dead bird and impaled it upon a stick, and stuck the 

 other end of the stick into the ground near some " scavenger" beetles. 

 The instinct which leads these insects to bury dead birds and other 

 animals as a provision for the wants of their young is well known. 

 In this case they soon found the bii-d but how was a bird perched 

 upon an upright stick to be buried in the ground ? After some con- 

 sultation they resorted to the very clever expedient of digging up 

 the stick, and then digging a hole large enough to bury both bird 

 and stick. Although this seems very like intelligence, it may possi- 

 bly be explained as a case in which the ordinary instinctive habit of 

 the animal accidentally fitted an exceptional demand upon it. 



Many of the actions of ants, however, do not admit of any such 

 interpretation. When two armies of ants of different species leave 

 their homes at the same time, arrange themselves in ranks, and march 

 to a point of meeting, and engage in battle, they exhibit, not simply 

 proofs of concerted action, but evidences that they can arrange and 

 plan to meet extraordinary and unusual emergencies. 



