PROOFS OF ORGANISING MIND 319 



that, in every case, first secretes, or as it were creates, out of 

 the protoplasm of the blood, special molecules adapted for the 

 2:>roductiou of each malcrial — bone, muscle, nerve, skin, hair, 

 feather, etc. etc., — carries these molecules to the exact part 

 of the body where and when they are required, and brings into 

 play the complex forces that alone can 1)uild up with (ri-eat 

 rapidity so strangely complex a structure as a feather adapted 

 for flight. Of course the difficulties of conceiving how this 

 has been and is being done before our eyes is nearly as great 

 in the case of any other specialised part of the animal body; 

 but the case of the feathers of the bird is unique in many ways, 

 and has the advantage of being wdiolly external, and of being 

 familiar to every one. It is also easily accessible for examina- 

 tion either in the living bird or in the detached feather, which 

 latter offers wonderful material for microscopic examination 

 and study. To myself, not all that has been written about 

 the properties of protoplasm or the innate forces of the cell, 

 neither the physiological units of Herbert Spencer, the pan- 

 genesis hypothesis of Darwin, nor the continuity of the germ- 

 plasm of Weismann, throw the least glimmer of light on this 

 great problem. Each of them, especially the last, help us to 

 realise to a slight extent the nature and laws of heredity, but 

 leave the great problem of the nature of the forces at work in 

 growth and reproduction as mysterious as ever. IModern 

 physiologists have given us a vast body of information on the 

 structure of the cell, on the extreme complexity of the proc- 

 esses which take place in the fertilised ovum, and on the exact 

 nature of the successive changes up to the stage of maturity. 

 But of the forces at work, and of the power which guides those 

 forces in building up the whole organ, we find no enlighten- 

 ment. They will not even admit that any such constructive 



guidance is required ! 

 * 



A Physiological Allegory 



For an imaginary parallel to this state of tliinirs, let us 

 suppose some race of intellia'cut beings wlio have tlie j)Ower 



