THE GENESIS OF LIVING ORGANISMS 229 



indebted to Wasmann for intimate knowledge of an especially 

 typical instance. A little weevil, the so-called " funnel- 

 roller," after its first flight settles on a birch-leaf, in which it 

 makes an incision along a line which we human beings could 

 discover only with the help of higher mathematics. Then 

 the beetle works on the veins, and rolls the leaf together into 

 a cone-shaped bag, which it closes by pushing in the tip. 



The whole action develops with unfailing certainty and 

 absolute control both of the anatomical and physiological pro- 

 perties of the leaf. As soon as the eggs are deposited and 

 the little bag is sealed, the same thing is done with another 

 leaf, when again the same act proceeds with the same rhythm. 



These instinctive actions, repeated with the same rhythm, 

 remind one vividly of the formation of highly complicated 

 pseudopodia by certain amoebae. Apart from the fact that 

 the outcome of these actions is obliterated again in the case 

 of the amoeba, while in the case of the beetle it persists, the 

 resemblance is perfect. In both, the action proceeds 

 rhythmically and in accordance with plan, without any 

 mechanism being demonstrable. 



In the case of the amoebae we assumed that a certain impulse- 

 sequence conditions the formation of the pseudopodia. If we 

 likewise assume in the action-organ of the beetle the coming 

 and going of central pseudopodia in the protoplasm of the 

 brain-substance, the phenomenon is not explained, it is true, 

 but it is brought into line with familiar biological processes. 



Plastic, instinctive and actions based on experience indicate 

 that the invasion by the impulses expresses itself in the appear- 

 ance of fresh framework, which then proceeds to condition the 

 functional issue. 



Here we are once more treading on firm ground. Now we 

 may conclude that everywhere there are genes, which are 

 stimulated by a definite sequence of impulses to shape the 

 protoplasm in a definite direction. 



