Vitality and Organization of Protoplasm. 29 



mental ontogeny and experimental regeneration. The striking phe- 

 nomena of regeneration, and the discovery of the formative totipotence 

 of single blastomeres, and even of small fragments of egg-plasm, are 

 forcing upon biologists the conception, that_the_ complex organisni has 

 to be look'cd upon as esentially a unitary _wholc. and not as a mere 

 aggregate of a multitude of inferior beings. 



To apprehend at ji glance why aggregational theories have necessarily 

 failed to explain ontogenetic evolution one need only recognize that by 

 assuming a specific germinal unit, of whatever sort, to be capable of re- 

 producing a definite kind of cell as autonomous being, be it k liver cell, 

 a nerve cell or any other cell; that by adopting this aggregational hy- 

 pothesis the entire process of ontogenetic evolution is therewith already 

 presupposed and left wholly unexplained. For the multicellular organ- 

 ism is being here regarded as a mere aggregate of diverse autonomous 

 cells, and its collective germ-cells as mere clusters of germinal units, 

 each of which possesses the powers to reproduce the kind of cell of which 

 it is the special germ. And it is just as difficult to account for the evo- 

 lution of a germinal unit into, for instance, a nerve cell, as it is to 

 account for ontogenetic evolution in general. ■ Ontogenetic evolution of 

 the multicellular adult organism can consist here only in the separate 

 ontogenetic evolution of the germs of each kind of its component cells. 

 The ontogenet'ic process running thus its full course unexplained in 

 each germinal unit, it is in relation of the multicellular organism like- 

 wise taken for granted in all its evolutional stages, from its germinal 

 beginning to its completed evolution ending in the adult organism. 



It is, therefore, obvious that, despite most ingenious and diligent en- 

 deavors on the part of a great number of competent investigators, the 

 sway of preconceived doctrines has prevented them from gaining in- 

 sight into the real process of ontogenetic evolution. They have merely 

 given minute attention to its morphological appearances and results, 

 without the remotest understanding of their mode of production. This 

 can not be attained before the conditions which give rise to the vitality 

 of the living substance are first understood. For ontogenetic evolution 

 is only a special outcome of that which constitutes the vitality of the 

 livinar substance. 



