DEATH 



vehicles of life. In their constant decay and recon- 

 struction consists the process of life, which expresses 

 itself in the great variety of vital phenomena." The 

 relation of assimilation (the building-up of the biogens) 

 to dissimilation (the decay of the biogens) may be ex- 

 pressed by a fraction to which the name biotonus is given 

 a|d. It is of radical importance in the various phenom- 

 ena of life. The variations in the size of this fraction 

 are the cause of all change in the life-expression of 

 every organism. When the bio tone increases, and the 

 metabolism quotient becomes more than one, we have 

 growth; when, on the other hand, it falls below one, 

 and the biotone decreases, we have atrophy, and finally 

 death. New biogens are constructed in regeneration. 

 In generation or reproduction groups of biogens (as germ- 

 plasm) are released from the parent in consequence of 

 redundant growth, and form the foundation of new 

 individuals. 



The phenomena of regeneration are extremely varied, 

 and have of late years been made the subject of a good 

 deal of comprehensive experiment, especially on the side 

 of what is called "mechanical embryology." Many of 

 these experimental embryologists have drawn far-reach- 

 ing conclusions from their somewhat narrow experiments, 

 and have partly urged them as objections to Darwinism. 

 They imagine that they have disproved the theory of 

 selection. Most of these efforts betray a notable lack of 

 general physiological and morphological knowledge.. As 

 they also generally ignore the biogenetic law, and take 

 no account of the fundamental correlation of embry- 

 ology and stem history, we can hardly wonder that 

 they reach the most absurd and contradictory con- 

 clusions. Many examples of this will be found in the 

 Archiv fur Entuuickelungsmechanik. When, however, we 

 make a comprehensive survey of the interesting field of 

 regeneration processes, we discover a continuous series 



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