14 Vitality and Organization of Proioplasm. 



throughout. But cells prove to be, on the contrary, minutely differ- 

 entiated and organized beings. This, at any rate, is the generally ac- 

 cepted view. Pangenesis would then require, as Darwin himself asserts, 

 special gemmules representing each differentiation of the cellular struc- 

 ture, and this would so complicate the already untenable hypothesis 

 as to amount, here also, to its complete overthrow. 



Pangenesis has been shown to be not only self-destructive, but de- 

 structive also of the cell-theory, which it acce^Dted as the foundation 

 upon which to erect its fanciful superstructure. 



Perigenesis — Hdecl-eh 



Haeckel found himself unable to adopt Darwin's h3^pothesis of Pan- 

 genesis and offered in its stead, under the name of the "Perigenesis of 

 the Plastidule," a different interpretation of heredity and ontogenetic 

 evolution. Haeckel believes material atoms to possess certain psychical 

 properties underlying their attractions and repulsions, and he assumes 

 the plastidules or ultimate vital units of which he holds organisms to be 

 composed, to be moreover endowed with memory, similar to that which 

 Ewald Hering had ascribed to organic matter. To this psychical en- 

 dowment of the plastidules he attributes the power of reproducing 

 definite modes of motion caught up and impressed upon them during 

 their phyletic interaction with external influences. Hereditary traits are 

 thus held to be conveyed from generation to generation by means of 

 these specifiically memorized plastidule-motions, which in the form of 

 complexly cumulating waves are transmitted from the reproductive 

 germ-plastidules to such as are thereby ncAvly produced in the course 

 of ontogenetic evolution. With Haeckel, ontogenetic evolution x^on- 

 sists, therefore, in a deployment and proliferating transmission of 

 phyletically acquired wave motions emanating from the plastidules of 

 the germ-cell. These transform by force of tbeir specific wave-motion 

 at all stages of the evolutional progress nutritive material into equivalent 

 plastidules, by whose co-operation the adult organism is eventually 

 built up. 



To this rather strange hylozoic hypothesis it may first be objected, that 

 from a scientific, and also from a philosophical standpoint it has been 

 found inconceivable how a psychical property, such as memory, whether 

 conscious or unconscious, can possibly set going any kind of motion. 

 The postulation of a psychical moving agent undermines the very 

 groundwork of physical science. Allow any sort of psychical influence 

 to move matter, and there can be no further dependence on a physically 

 ordered cosmos. But scrutinizing Haeckel's conception somewhat closer 

 than he has himself been led to do, it will be found that it amounts, 

 after all, only to a statement of a chemical fact in terms of hypothetical 

 motion. For in his own words: "Conditions of nutrition change the 

 chemical constitution, and therewith the molecular motion of the plasti- 

 dule." And so it turns out, that it is the chemical constitution of the 

 plastidule which is underlying its so-called memory, as well as its hj'po- 



