TRANSMISSIBILITY OF FUNCTIONAL MODIFICATIONS 79 



basis for selection. Osborn says very neatly in this connexion, ' We 

 see with Weismann and Galton the element of chance ; but the dice 

 appear to be loaded, and in the long run turn " sixes " up. Here arises 

 the question : What loads the dice ? ' 



Until recently we might have answered, ' external conditions ' : 

 it is they that load the dice one-sidedly, and condition that the same 

 straight path of phylogenesis is adhered to, and exactly the same 

 direction of variations is preferred and maintained. It has to be 

 asked, however, whether this answer, which is certainly not absolutely 

 incorrect, is sufficient by itself, whether the dice are not falsified and 

 one-sidedly loaded in another sense, so that they always throw a 

 preponderating number of the useful variations. We shall attempt 

 very soon to solve this problem, but in the meantime I must refer 

 to another argument in favour of assuming the Lamarckian principle, 

 perhaps the most important and it may be thought the most difficult 

 of all to refute, the so-called co-adaptation of the parts of an organism, 

 that is, the fitting together of many individual organs for a common 

 purposeful functioning. 



