THE CELL-STATE. 175 



Nature continues eternally young ; the earth adorns itself every 

 spring with leaf and flower, having the same freshness and youthful 

 vigor as when for the first time He " let it bring forth grass, the herb 

 yielding seed, and the fruit-tree yielding fruit after his kind." The 

 grasses and flowers, it is true, which this year are cut or withered, 

 the leaves and blossoms which the wind has to-day blown from the 

 trees, will not assist in forming its robe in the next spring, but Nature 

 draws out new shoots from the old roots, new leaves from the old 

 branches, and thus rejuvenates herself with every new year. And 

 although the human race, although also the other kinds of animals and 

 plants, show as yet no trace of age in spite of the numerous thousands 

 of years in which they have dwelt on the earth, still each individual is 

 perishable, it grows old and dies ; but new generations shove them- 

 selves uninterruptedly into the gap, so that the whole abide in the fresh- 

 ness of youthful vigor. Rejuvenation so dwells in nature that every 

 individual runs through a limited circle of development, and is finally 

 worn out and cut off, to be replaced by fresh members which pass anew 

 through the accomplished cycle. 



If we apply this view which we have gained of the rejuvenation 

 of nature to the consideration of a single being, whether it be man, 

 animal, or plant, we shall perceive that all life rests upon a constant 

 renewal. Life is an uninterrupted contest with death, which attacks 

 it every moment, but is beaten back by rejuvenation. It would be an 

 error to represent a living being as anything constant, its appearance 

 as anything steady ; life in truth resembles a water-fall, which only 

 apparently preserves a constant form, while in reality none of the par- 

 ticles of water keep their places, but are continually removed and re- 

 placed by new ones. The visible form of stillness is kept up only in 

 perpetual movement. Life resembles a flame, which restlessly con- 

 sumes itself and can shed an even light only when new particles come 

 up in place of those which have been burned, only to be dissipated in 

 their turn a moment later. So in living bodies the combination and 

 arrangement of the matter on which their outer form and internal 

 disposition depend are at no two instants the same, but an uninter- 

 rupted change of matter is taking place. The particles which are 

 together in this moment at one point are in the following moment 

 separated and replaced by others. For only a short time are the atoms 

 of which bodies are built up adapted to the service of life ; sooner or 

 later they leave it in order to follow the free play of the forces of 

 attraction which join the elements in the enduring combinations of 

 lifeless nature. Therefore, the living body is obliged constantly to 

 take up from without new elements of nourishment, by means of 

 which it repairs its loss ; and these insinuate themselves so closely in 

 the place of the separated ones, that even the eye of the naturalist, 



