CAUSE OF HEREDITY 305 



quired and necessary under the particular circumstances. 

 Take for example the life and development of a butterfly. 

 The egg is laid in the fall and in the spring this egg, a 

 single cell, multiplies and with the material furnished by 

 the parents and at hand, such as the leaves of plants and 

 trees, builds itself into a structure like a worm and moves 

 about, filling this structure during the summer with, more 

 building material to be used later on; this worm or cater- 

 pillar is now a moving structure like an animal or automo- 

 bile. The next thing that happens is that towards fall 

 this moving structure changes into a chrysalis which is 

 a stationary structure. 



What is the purpose? It is for the purpose of chang- 

 ing later on into a flying machine. The worm or cater- 

 pillar takes part of himself and with this material builds 

 a house or covering around himself; then he tears him- 

 self to pieces and rebuilds himself into an aeroplane and 

 occupies the house first built as a work shop, while re- 

 building himself into an aeroplane or flying machine. 

 However, we must remember that it is not the. worm or 

 caterpillar that does these things, it is the cells of which 

 he is composed and which put him together in the first 

 place. They take the first structure, the worm, apart, 

 tear it down as man would a house and with the same 

 material build a new structure, a flying machine the 

 butterfly. Now you will notice that in this case as in a 

 great number of other cases, like does not produce like. 

 The worm does not produce a worm nor does the butterfly 

 produce another butterfly. In this case, the worm pro- 

 duces a butterfly and the butterfly produces an egg. Their 

 heirs are in no way similar to themselves. The fact is 

 that no animal or plant produces anything, it is the cell 

 that produces. In the same manner the submarine or 

 house does not produce anything; it is the builders of 



