UNSOLVED PROBLEMS. 143 



Possible solutions of the problems in question have from 

 time to time been offered by ingenious, imaginative men. 

 Such suggestions are not to be despised or rejected until at 

 least they have been rigorously applied by competent expe- 

 rimentalists to the facts. The suggestions alluded to, that 

 are applicable, or that have been applied, to different cases, 

 include the following : that 



1. The lower animals use their senses in ways unknown 

 to man ; their senses, moreover, though the same in kind 

 with his, being much more acute or delicate. The special 

 senses involved are smell, vision, and hearing. 



2. Certain animals, and perhaps man himself, possess 

 additional or supplementary senses, such as a sixth sense of 

 direction, locality, way-finding or homing, or of polarity 

 an intuitive knowledge of the points of the compass. 



3. The lower animals, or certain of them, are susceptible 

 to various influences that do not affect man. 



4. There may be much unconscious observation on the 

 part of the animals, unnoticed observation on the part of 

 man. This may include, for instance, attention to the posi- 

 tion of the sun, the noticing of landmarks and their topo- 

 graphical relations. 



5. Unknown faculties, instincts, or susceptibilities may 

 exist. 



6. Powers or capacities that are usually latent may be, as 

 Bishop Butler suggests, called into action. 



One of the commonest and best illustrations of pheno- 

 mena at present or as yet unexplained is the way- or home- 

 finding by the dog, horse, ass, cat, and other animals over 

 ground previously unvisited by and therefore unknown to 

 them. I am leaving out of view all cases in which, by any pos- 

 sibility, memory or observation could have been, or probably 

 were, operative for instance, in the flights of courier or car- 

 rier pigeons and refer only to those numerous cases in which 

 various pet animals hare been taken by masters or mistresses 

 long distances from home by routes previously untraversed, 

 in conveyances varying extremely in their character, and 

 have found their own way home by a different route, usually 

 the shortest and most direct, equally unknown to them, and 

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