226 Causes and Course of Organic Evolution 



stance for display of biotic energy; the cognitonucleus for 

 condensation and distribution of cognitic energy; the cogito- 

 nucleus in htemoflagelhites, or the neuroneme substance in 

 some cihate Infusoria, for condensation and distribution of 

 cogitic energy; and the gameto- or micronuclear substance 

 that gathers up, condenses, and hereditarily hands down to 

 future generations the peculiarities of the species. 



These however exactly represent the four fundamental cell- 

 types or cell substances that are characteristic of metazoan 

 animals. And of the four, the cogitonuclear or the nervous 

 and the gametonuclear or reproductive are of special signifi- 

 cance. We defer study of the latter till the succeeding chap- 

 ter. But a distinct evolution and segregation of nervous 

 substances is of high value amongst Protozoa, for it anticipates 

 and explains the origin of the ganglionated or cogitic system 

 of Metazoa. 



As compared mth the chromatin or cognitonuclear substance 

 of plants and of simple Protozoa, this more complex neural 

 cell substance initiates that striking peculiarity of animals 

 that we call reflex action. Such action seems to be entirely 

 absent from even the highest and most sensitive plant organs, 

 whether these be the actively motile cells of Chlamydomonas, 

 or the delicately responsive tissues of Mimosa pudica — the 

 sensitive plant — and Dioncea muscipula — the Venus fly-trap. 

 We may therefore essay, at this stage of our inquiry into pro- 

 environal reaction, to learn how such concentrated nerve 

 substance originated from simpler substance. This will carry 

 us back to a consideration of the nature and distribution of 

 chromatin or cognitic substance. 



If chromatin be truly a sensory or cognitic material, its 

 fundamental function would be to condense and then to con- 

 centrate inwardly tubes of energy that would represent the 

 fundamental energies of the world that environs each organ- 

 ism. That is, the nine fundamental sense-centers that we 

 have already postulated, the thermotactic, the heliotactic, 

 the chemotactic, the geotactic, the jKiraheliotactic, the hydro- 

 tactic, the mechanotactic, including the touch and sound 



