REJUVENESCENCE IN NATURE. 



here the lamellar deposition of the coat of the cell betrays 

 the internal vibration of the formative activity. On the 

 other hand, the phenomena of Rejuvenescence appear so 

 much the more striking and surprising, the deeper the 

 depression of life preceding the new upraising ■ and the 

 more distinct, consequently, the separation of the new- 

 lease of life from the old, the more perfect the con- 

 sumption and breaking through of the old structure by 

 the new. The metamorphoses of insects furnish most 

 beautiful examples. 



Inquiring into the causes of the phenomena of 

 Rejuvenescence, we recognise that external Nature, amid 

 which special life displays itself, acts in calling and awaken- 

 ing through the influences which the seasons of the 

 year, nay even the hours of the day, bring forth; but the 

 proper internal cause can only be found in the tendency 

 towards completion, which is present in every existence 

 according to its kind, and drives it to subordinate to itself 

 ever more completely the foreign and external world, to 

 shape itself within it, as independently as the specific 

 Nature allows. At the same time, however, a term 

 is set to the task, beyond which the phenomena of Re- 

 juvenescence do not proceed. As in mental life there is 

 a time of maturity, when youth and age are as it were 

 intermingled, when the restless strife of acquisition and 

 destruction ceases, when motion is paired with rest, so 

 also in the physical and corporeal there is an analogous 

 condition of maturity and relative rest, when the alterna- 

 tion of destruction and reformation is only carried on 

 in the small vibrations of the interchange of material, 

 maintaining vital motion and guarding against its being 

 benumbed. In animals we see this condition com- 

 mence when the organism has attained completion, is 

 "grown-up" as it is called, when nothing more new is 

 formed, but the actually existent enters upon its predes- 

 tined function, into its service in the more elevated side of 

 animal life. In Vegetable life we see the corresponding 

 phenomenon in thefruit, which Aristotle already regarded as 



