208 HEREDITY. 



7. On the basis of this double identity stands the 

 supreme law of hereditary descent, — that every or- 

 ganism breeds true to its kind. 



It is vastly important that we should take these 

 earliest steps with great caution, and be sure of our 

 ground at every point. "We demonstrate by its 

 effects that the co-ordinating power is transmitted 

 in hereditary descent. We are sure, from all our 

 previous arguments, that this co-ordinating power 

 does not belong to matter. We have proved here, 

 we think, that life in physical organisms is the 

 power which co-ordinates the movements of germi- 

 nal matter. That co-ordinating power existed as one 

 life : now it exists as two lives. So much is certain. 

 You say that it has divided itself. Very well ; do 

 not look into mysteries to-day. I do not know how 

 one individual becomes two. The angels gaze on 

 that casket, and do not understand what is within it. 

 I am not pretending to illuminate mysteries. What 

 we know beyond doubt is that in a self-divided or- 

 ganism one life becomes two lives. How one indi- 

 vidual becomes two individuals, science does not 

 know. We know that one does become two, but 

 not hoiv it does. When we examine facts, however, 

 we can trace the action of this double identity, 

 physical and immaterial. This undeniable circum- 

 stance explains much. Every organism breeds true 

 to its kind, and it does so because a double identity 

 exists between parent and child. 



Self-multiplication by the division of organisms 

 involves a production not only of two lives, but 



