4o8 LIFE : OUTLINES OF GENERAL BIOLOGY 



for hormones said to be present also, show some equivalent of 

 neural process, and after stimulations such as we know as readily 

 of sensory character: while again the integration of each plant as a 

 characteristic whole, despite the frequent modifications impressed 

 by external environment, presents a unity which we cannot con- 

 ceive as simply organic without something of psychic as well. 

 IVotopsychic though that may be, who can say more for the chick 

 within the egg, or even for the unborn child? 



Sleeping and sub-conscious though such life be, must we not 

 realise — as experimental studies of sleep, hypnotic state, etc., all 

 tend to show — that the sub-conscious state is consistent with a 

 certain measure of what we cannot but call sensing, experiencing 

 and feeling — surely even of proto-emotional thrilling, sub-ideative 

 urging, and so in animal forms with neuro-cerebral and proto- 

 psychic changes and interactions, towards definite behaviour and 

 consciousness later? Without some such continuity and association 

 of incipient neural functioning with its psychic equivalent, how 

 can we imagine the needed and obvious organic and psychic func- 

 tioning of maturer life at all? 



Before reading anything of the modem psycho-analyst's library, 

 with its exposition of the sub-conscious, and this even to its sub- 

 stantial identification of the Hindu mystic's ideal of "Samadhi" 

 (and perhaps that of the Buddhist's Nirvana also) with the placid 

 bliss of sleeping infancy, even unborn, it was of no small interest 

 to find, on long rides with Bose through Himalayan forest-glades 

 and flowers, that on our different lines of scientific reasoning, as 

 well as in speculative ways, we had alike come to the same con- 

 ception as that so often expressed in Western poetry, and in Hindu 

 religion and philosophy as well — of plant-growth and flowering as 

 at once expressing the organic health and fullness, the beauty and 

 even the ecstasy of Life, perfected and at one. 



COLOURS AND PIGMENTS 



Coloured substances or pigments of many kinds play a manifold 

 part in the life of organisms. In some cases, indeed, they may 

 be called essential, as in the green pigments of plants and the 

 red pigment of the blood of backboned animals. Apart from pig- 

 ments there may also be great utility in colour; thus it is useful 

 to the ermine {Musicla crminea), to the mountain-hare [Lcpus 

 variabilis), to be white in winter; but there is no pigment involved 

 in the whiteness. Conversely, some important pigments, such as 

 the cytochromes involved in oxygen control, contribute little or no 

 colour to the tissues in which they occur. 

 What Colour Means.— It is not possible to understand colour 



