SIDE LIGHTS ON BIRDS 



which may compensate them for the loss of child- 

 hood, is that they are the only living animals 

 which can logically lay claim to physical im- 

 mortality. The individual, in fact, never dies. 



A second class exists in which the new arrivals 

 on this material plane have a prolonged period 

 of childhood, but they are born in a state alto- 

 gether different from that of their parents, and 

 gradually rise to a higher stage, reaching at last 

 the parental development. Insects provide the 

 most numerous examples of this class, and here 

 we find the exceptions to the rule, " the longer 

 the life, the longer the childhood," a rule which 

 governs all the more highly placed species. In 

 certain of the cicada, we have the extraordinary 

 fact that no less than 17 years is spent in a state 

 of immaturity in order to qualify the insect for a 

 brief 15 days' existence in the upper air, which is 

 roughly as though a man destined to live 70 

 years were obliged to devote 68 or 69 of them to 

 helpless babyhood, in order that he might enjoy 

 a manhood of the few remaining months. 



In the instance of butterflies, again, we have 

 a striking example of this second class. Judged 

 by ordinary scientific definitions, the caterpillar 

 is a creature of altogether different species from 

 the butterfly. In structure, in habit, and, in- 

 deed, in every particular which goes to con- 

 stitute a species, the caterpillar stands as far from 

 the wonderful winged creature it is destined to 

 become, as a man stands from one of Gustave 

 Dore's Angels. True it is that in both cater- 

 pillar and man there are certain peculiarities, 

 even in the physical structure, which are cal- 

 culated to give rise to what Wordsworth de- 

 scribed as " forward-reaching thoughts." A 

 naturalist, who had no knowledge of the exist- 

 ence of a butterfly, and who was perforce obliged 



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