CoGNiTic State of Energy 143 



We shall not at present consider the higher animals in which 

 nerve-cells are evolving or have attained a high degree of 

 complexity, since these will be studied in relation to cogitic 

 energy in a subsequent chapter. 



But, before closing the present one, short account may be 

 taken of some well-knowTi phenomena, in which biotic and 

 cognitic energy seem to play a conjoint part, as must in the 

 great majority of cases be true, could we only analyze them up 

 in a sufficiently accurate manner. The case above cited for 

 Infusoria is to the point. For while the chemotactic perception 

 of food, the mechanotactic ingestion of it, and the digestive 

 changes that are effected in it are all, we would consider, cor- 

 related expenditures of biotic energy, the increasingly rapid 

 and alert movements that are correlated and directed to the 

 above end, the manner in which such activities become reduced 

 by age as sho^voi by Maupas's experimental cultures, the slow 

 but steady modification of structure so as to constitute varia- 

 tional and at length specific differences, and the transmission 

 of such by sexual heredity we would regard as due to chromatin 

 or nucleo-nucleolar structures, that are traversed by cognitic 

 energy. 



Some cases however, in which temporary reduction or dor- 

 mancy of the cognitic flow of energy, and continued action of 

 the biotic, deserve notice in the present connection. Thus the 

 widespread phenomenon of sleep, that in plants we designate 

 nyctitropism, in animals slumber, equally represent a state 

 in which at fairly regular intervals, and particularly on the 

 approach of darkness, the entire cognitic energizing network 

 becomes gradually more flaccid, irresponsive, and passive. 

 In nearly all such cases definite positions are naturally assumed, 

 as for example, fall or rise in leaflets or leaves, horizontal posi- 

 tion in many animals, erect perching position in many birds, 

 hanging position in bats, etc. The senses become almost or 

 wholly incognizant of surrounding stimuli, unless these be of 

 greater than normal intensity. 



But the flows of biotic energy, though reduced in intensity, 

 still proceed in even manner; digestion, respiration, growth. 



