122 STUDIES IN LIFE AND SENSE. 



pursue their journeys by night, when the sense of sight is either 

 practically unavailing, or may be regarded as being of comparatively 

 little use. The discussion of this subject may only be profitably 

 carried on in the light of higher knowledge ; but, as will presently 

 be noted, the consideration of the determining causes of migration 

 leads us to believe that the unerring flight of migratory birds, as 

 well as the exactitude of their arrival in their summer home, and 

 of their departure for their winter haunts, are regulated by the force 

 of long continued "habit," and by the influences of "inherited 

 instinct." 



No two factors are of greater import, or exercise a more despotic 

 power over the fortunes of lower life, than " habit " and " instinct." 

 By their aid animals accomplish unerringly, and it may be uncon- 

 sciously, acts and labours which the educated experience of human 

 kind would perform but imperfectly, in which experience would alto- 

 gether fail. Witness in proof of this statement the perfection of the 

 acts and duties in which the bee, wasp, or ant engages from the first 

 moment of existence. The very perfection of the act as performed 

 by these unreasoning creatures is, as Dr. Carpenter has remarked, a 

 proof of the non-intelligent and purely instinctive nature of the 

 beings which perform it. Otherwise, indeed, the perfection of their 

 labours must be held to surpass that attained by the human reasoner. 

 And so is it, we opine, with birds, with the guidance of their flight, 

 and with the exactitude of their seasons. Admit the influence of 

 inherited habit, and we find a mysterious power of guidance sup- 

 plied by instinct to- the migrating bird, just as the young worker-ant, 

 liberated from its swaddling-clothes, proceeds, without any training 

 other than the directive force of instinct and habit inherited from its 

 predecessors and progenitors, to discharge its duties with the punctu- 

 ality and perfection of the mature and adult insect. How the habits 

 which instinct directs, and which heredity, or the law of " like 

 parent, like child," propagates, have been acquired is a matter for 

 after consideration. Once, however, admit the acquirement of the 

 habit, and its continued performance by the species, and the laws of 

 descent and likeness will accomplish the rest. It is true that a wider 

 range of senses and faculties than that of which physiologists are as 

 yet cognisant in man, may be the property of many of the lower 

 animals. Sight and memory in their special phases of development 

 as applied to the guidance of a carrier-pigeon, for example must be 

 of a character much more acute and strong than we are accustomed 

 to regard these faculties as represented in human existence. And 

 if to acute senses we add the idea of the unconscious, but unerring, 

 direction of instinct and habit, strengthened by transmission through 

 extended epochs of time, we may perchance discover a rational 

 means of approaching the solution of the mystery whereby the bird 



