112 WALTER RIDD, M.D., P.Z.S., ON 



-of the wards, but it is of vastly greater interest when the 

 lock to which it is adapted i?5 also investigated by one who 

 is competent to understand its working and make. The two 

 must be looked at together, and, broadly speaking, a key is 

 for a lock and a lock for a key. This instance introduces the 

 ■environment side of organic existence, and the latter is very 

 largely ignored, or taken for granted, and its bearing on 

 teleology not mentioned Avhen adaptations, adjustments of 

 the organisms themselves, are considered and expounded by 

 a one-sided " law." 



Before the bacteria of putrefaction could commence their 

 beneficent work as scavengers of the globe, they require for 

 their own life a measure of moisture, warmth, oxygen and 

 organic material, before it becomes of the least importance 

 "whether or not they are adapted. The environments referred 

 to must exist before they can do so. And so it is through 

 the vast ascending series of protophyta, protozoa, metazoa 

 up to man. Suited environments must jyrecede the life of 

 any one of these forms of life, which become adapted to 

 them. When we scan in thought the immense stretch of 

 geological time, and the size and variety of the globe which 

 has been the theatre of an ascending scale of life, and 

 remember that to a great extent the environments of one 

 'epoch are not fully suited to the needs of the preceding and 

 succeeding flora and fauna, some dim idea of the importance 

 of the environment side of the question of adaptation is 

 reached. Selection has become the modern equivalent of the 

 Creator in the thought oi certain thorough-going scientists, 

 and its range claimed to be from nebula, to man, from the 

 -elements of matter to the productions of the hrmiau intellect. 

 In biology it has several aspects. At first there was only 

 known the natural selection of Darwin, then there came 

 physiological or sexual selection. Later there was conceived 

 by Roux a form of selection acting w^ithin the organism 

 itself, between the different cells of which it is built up, and 

 finally Weismann, recognizing the '• lowering clouds " with 

 which he saw Darwinism threatened, invented what he 

 called germinal selection. There are, then — 



1. Personal Selection, by which individuals among a group 

 are selected as being generally more fitted to survive. 



2. Sexual Selection, according to which certain individuals 

 among higher animals select one another for some attractive 

 • qualities or characters, and so these are propagated. Darwin 

 and Romanes are the authors of this form. 



