50 Vitality and Organization of Protoplasm. 



GENERAL REMARKS. 



It has been shown in this section that a definite cycle of chemical ac- 

 tivities constitutes protoplasm a living substance ; that its interaction 

 with the stimulating influences of the medium, taking place at its chem- 

 ically highest region, is its culminating function, to which all other 

 functions are subservient; and that this state of things necessarily in- 

 volves nutrition or restitutive assimilation on the one hand, and on the 

 other hand depuration or elimination of waste products. 



Howsoever intricately differentiated into organs, tissues and compo- 

 nents of tissues an organism may appear to sight, its structures are nev- 

 ertheless out and out the visible substratum of this -manifoldly related 

 and yet indiscerptible cycle of activities which constitutes the. vitality 

 and governs the organization of all living beings. It inseparably under- 

 lies the structural unity of the organic individual in all its varied forms 

 of appearance. 



Although since Descartes' purely mechamcal views, and then especially 

 since atomic mechanics have guided the interpretation of vital phenomena, 

 many prominent biologists have, notwithstanding, felt compelled to as- 

 sume, as help in their scientific explanations; a special vital force or 

 agency operative in vital phenomena. The existence of such a special 

 vital force Lotze first successfully combated in his celebrated article in 

 Wagner's Handwoerterbuch der Physiologic. He clearly showed that 

 that which had been called a "vital force" is a mere metaphysical fic- 

 tion. And though thoughtful observers such as Johannes Muller, Claude 

 Bernard, Liebig and even Virchow still adhered to the belief that some- 

 thing transcending physical forces is operative in vital manifestations, 

 the sway of atomic mechanics overruled until quite lately all attempts 

 to introduce into biology modes of activity additional to such as are 

 merely mechanical. 



The insufficiency of the purely mechanical interpertation of natural 

 phenomena in general and of vital phenomena in particular, was forced 

 upon the present writer during his protoplasmic researches, and insisted 

 upon in various publications for the last twenty-five years. In its rela- 

 tion to biology I have expressed this need of a more profound view per- 

 haps most concisely in Pfiueger's Archiv, 1881, v. xxv, p. 534, of which 

 I give a translation : "The power of regeneration is in all cases the me- 

 chanically unaccountable energy of protoplasm to chemically reinte- 

 grate itself. Consequently its actuating energies and even the mechan- 

 ical capacity for work on the part of animal organisms, does not admit 

 the application of exact physical methods. We have here before us as 

 source of energy an explosive substance, which is ever restituting itself, 

 and whose power of reintegration, grounded in endless phyletie elabora- 

 tion, stands therefore in no direct mechanical relation to its environment. 

 Neither the complemental restitution, nor the effects of stimulation, are 

 here mechanically transparent. They are. on the contrary, to be looked 



