i6 THE ACTIVE FORCES OF LIVING ORGANISMS 



statement, affording proof also that the red rays are 

 the most exciting. Violet is, as is well known, the 

 colour used in royal funeral ceremonies, and is 

 decidedly calming. Thus, we have, as it were, a 

 The two scale of colour and a scale of emotions, and it will be 

 seen that in discussing them we have passed from 

 one end of the spectrum to the other in the order in 

 which the various kinds of light are arranged accord- 

 ing to the length of their waves. One cannot believe 

 this to be mere hazard, and this agreement between 

 the two scales becomes of greater interest when we 

 reflect that the character of our emotions is probably 

 dependent on the mode of vibration of the molecules 

 of the nerve-cells. The movements of the latter 

 depend directly, it is true, on the intensity of certain 

 oxidation processes in the retina, but these in turn 

 are doubtless influenced in varying degrees by the 

 shade of the light by which they are started. 



In order to obtain a comprehensive view of many 

 of the most mysterious phenomena of life, it is very 

 important to consider the nature of the nuclei of cells. 

 The cell Within recent years it has been said that every cell 

 nucleus, either has, or at some time had, a nucleus. This 

 statement has been put forward rather as an article 

 of belief, than as a fact due to actual knowledge. In 

 certain unicellular organisms — such, for instance, as 

 the yeast plant — the existence of a nucleus has 

 frequently been doubted, but those who hold to the 

 opinion of its omnipresence allege that the particles 

 of which it is composed must become disassociated 



