60 Causes and Course of Organic Evolution 



If we now focus up the leading features of the Acaryota, it 

 may be said that it includes organisms whose protoplasm 

 responds to diverse chemical stimuli, much as would a complex 

 but equilibrated mixture of different colloids; that it shows 

 high adaptability to extremes of temperature, which may range 

 from at least 100° C. to — 200° C. under certain conditions; 

 that it can resist prolonged dessication; that it is affected by 

 all forms of energy to a greater or less degree, and reacts to 

 these correspondingly; that it shows extreme adaptability to 

 fresh, to brackish, and to salt water, or to a moist aerial envir- 

 onment; that it absorbs and radiates out supplies of energy 

 either of a thermic, lumic, chemic, or electric kind; that in all 

 of these features it resembles many well-known colloid bodies 

 of inorganic origin. But in that it shows varied means for 

 reconstituting its molecules, or in other words of continuously 

 nourishing itself, and simultaneously of throwing off waste 

 substances, it shows a marked degree of advance on even the 

 most complex or perfect colloid mixture at present known. 



With such intrinsic protoplasmic characters before us, the 

 question may next be asked, whether, as we rise in the scale 

 of diverging plant and animal life, we can still trace such as 

 more or less perfectly persistent hereditary characters, even 

 when alongside and interunited with such more delicately 

 organized and sensitive conditions as we hope later to show 

 have been introduced through evolution of the chromatin or 

 nuclear substance of the cell, and possibly other constituents of 

 more complex nature associated with the chromatin? We 

 consider such to be the case, and to constitute the explanation 

 for many rather puzzling biological phases in plant and animal 

 life. 



To pursue this inquiry somewhat further now, it is a well- 

 known fact that, while most plants and animals show a greater 

 sensitivity in their life relations during the actively growing 

 or vegetative phase, they often tend to reach a stage where, 

 either from direct environal agency — as in intense insolation 

 and dessication of fungoid spores, lichens, etc., amongst plants, 

 or rotifers amongst animals — or at a definite stage in their 



