24 THE EVOLUTION OF CONTINUITY 



become extinct. Similarly, in the facultative mottling of 

 certain flat fish, or the green colouring of certain insects, 

 the detection of the purpose of protection or concealment 

 in no way increases our knowledge. We wish to find causes, 

 and conclude that in both the examples mentioned the 

 colouring is ultimately the inevitable effect of environmental 

 cause, and that the capacity for concealment is equally 

 inevitable. 



Thinking on these lines, let us take the case of a multi- 

 cellular animal. This grows as a potential Individual till 

 it reproduces itself, or (as we shall see later) more correctly, 

 till through its growth there occurs the reproduction of one 

 or both of the original entities with whose fusion the 

 growth-cycle began. We reason that the animal grows or 

 enlarges because its component cells do likewise, and in a 

 spurious way " reproduce " themselves ; and, taking it for 

 granted that a fundamental law is at work, we may conclude 

 that the growth and multiplication of the cell is the multiple 

 expression of the growth of its component parts, and so 

 backwards, till we stop at the multiplication of ultimate 

 growth-units by a process of addition. At the present time 

 we do not truly know what the ultimate material unit is, 

 but in a series of progressive multiples any one of these 

 serves as a common factor for those succeeding it, so that 

 the matter is not of absolute importance. 



As a general statement it may be said that every living 

 Individual in Nature grows to reproduce itself, but this is 

 not literally correct, or is only half the truth ; for while 

 reproduction is the inevitable result of normal growth, it 

 is not, strictly speaking, the Individual which is reproduced. 

 The growth-cycle begins with the union of sexual elements, 

 and it is these which are reproduced at the end of the cycle 

 after having temporarily lost their identities. The Individual, 

 as will be shown, is really the sum of the reactions involved 

 in the restoration of the sexual elements, and the alternating 

 loss and recovery of their identities in a given line of descent 

 involves the reappearance of the intermediate " reactions " 

 composing the evanescent Individual. Understanding this, 

 however, we may call this reappearance " reproduction," 

 and say that while from the loss of sexual element identity 

 evolves the reproduction of the element, so also does the 



