48 



Vitality and Organization of Protoplasm. 



i^iccfyl^--' 



( 



wise a j^rocess of reintegration^ due to the same restitutive power in- 

 herent in chemical fragments derived from adult organisms, and here 

 called reproductive germs. If a minute fragment artificially and neces- 

 sarily more or less clumsily severed from the egg of an Echinoderm has 

 , power to reproduce so complex and specific a structure and form as 

 that of a pluteus ; and a small irregular slice of the substance of Stentor 

 power to reproduce the definitely formed and organized Infusorium, 

 it is, surely, no very bold leap in the dark to conclude that the infinitely 

 more refined methods of organic development have succeeded in normally 

 detaching from tlie living substance of ever so highly constituted or- 

 ganisms more or less minute germinal fragments, which as such retain 



I the power to reproduce the structure and form of the adult organism 



[^ from which they are derived. 



Germs of all kinds may then rightly be looked upon as chemical frag- 

 ments or radicals, which by means of complemental assimilation of nutri- 

 tive material gradually grow to adult stature, reproducing thereby the 

 structure and form of the organism from^wlnch they originated. In 

 1880 I expressed this fundamental biological fact in the following terms: 

 "Any portion of the unitary protoplasm of an organic individual, and 

 especially its so-called germs, have to be considered in the strictest sense 

 of the term, chemical radicals. You remove from a chemical compound 

 a part of its integrant atoms; it is no longer saturated, but represents 

 a chemically disequilibrated residue with combining powers corresponding 

 to the severed atoms. Whenever occasion 'offers the radical will become 

 resaturated ; it will in fact restitute itself, Avill restore the integrity of the 

 compound which it radically represents. Surely it is this admitted 

 chemical occurrence which underlies the vital phenomena of growth, 

 repair and reproduction." ("The Unity of the Organic Individual" 

 Mind v., pp. 465-489.) 



The results of experimental regeneration and experimental ontogeny; 

 the latter dating from Pflueger's experiments on the eggs of frogs, 1883, 

 and extended since by numerous observers ; these results closely corrobo- 

 rate the views forced upon me by the study of primitive protoplasmic 

 individuals, as will be fully explained in the section on "Organization." 

 By watching the sundry modes of reproduction of various kinds of 

 Protozoa a pretty clear insight into the intimate workings of the process 

 may be obtained. Self-division into two equally formed and organized 

 halves; an occurrence wholly unintelligible to aggregational and me- 

 chanical theories, consists really in a most elaborate process of complete 

 reintegration. It starts from two independent centers of reproduction, 

 arising within the substance of the protoplasmic being. It is in no way 

 connected with overgrowth as usually asserted; for it may occur at dif- 

 ferent stages of ontogenetic evolution. It is caused by conditions that 

 are obstructing the unitary cycle of chemical activities which consti- 

 tutes the protoplasmic individual; or it is caused by conditions favor- 

 inw otherwise the independent formative activity of parts of tlie living 



