60G Causes and Course of Organic Evolution 



the same reason the sense of personal identity, the unity of 

 individual character, is confused and seemingly lost." And 

 again, "How can there be a clear sense of the unity of the ego, 

 how any conscience, when there is an entire abeyance of that 

 coordination of mental function, the self-consciousness of 

 which is the feeling of personal identity.'* 



Many of the transition stages or variation phenomena of 

 sleep might well be interpreted, if we consider that the normal 

 or waking passage of cognitic and cogitic energy becomes re- 

 duced in amount or in intensity, through gradual exhaustion 

 of the supplies of biotic energy from the protoplasm as com- 

 ]>ared with the amount used up. But the sleep-period is the 

 time when biotic activity continues in practically undiminished 

 vigor and distribution of abundant biotic energj^ in the form 

 of digested, absorbed, and assimilated food, is proceeding. 

 So a gradual recuperation of sense-perceptive or chromatin, 

 and also of mental or neuratin substance proceed, till this very 

 process results in reaccumulated cognitic and cogitic energy 

 that stimulates to waking. Maudsley has advocated the view 

 that waking does represent a gradual reaccumulation up to an 

 optimum stage, of constituents that by diurnal activity became 

 reduced to a minimum. 



From the observations of Durham also (199), confirmed 

 by several subsequent workers, the sleep process is attended by 

 reduced flow of blood to the brain, and passage of it to the 

 vegetative organs. So, though the relative activity of digestion 

 may then be less than during day, its calm and uninterrupted 

 procedure, followed by absorption of the food, supplies material 

 for the biotic flow that in turn is in part converted into cognitic 

 and ultimately into the highest or cogitic phase. Waking 

 seems therefore, physiologically, to be an optimal reestablish- 

 ment of stores of cognitic and cogitic energy from the biotic 

 system, succeeding to a state of more or less marked reduction 

 of such stores, when the state supervenes that we term sleep. 

 During tlie latter state the biotic system alone functions 

 steadily, the cognitic and cogitic are in a state of minimal 

 activity. 



