TRANSMISSIBILITY OF FUNCTIONAL MODIFICATIONS 



9/ 



without any intervention of the Lamarckian principle, and that there 

 must be some other factor which brings this about. 



Where, then, shall we look for this other factor, if not in the 

 processes of selection, in the selecting of the most suitable variations 

 among all those which occur ? We are confronted with the alternative 

 of either working out a sufficient explanation with this factor, or of 

 giving up the attempt at explanation altogether. Yet the application 

 of the principle of selection in relation to the neuters of colony- 

 forming insects is by no means simple, for, as the workers are 

 sterile, a modification of them through processes of breeding cannot 

 begin directly with themselves. The workers which exhibit the most 



Yiir. io6. Three workers of the same species of Indian Ant (Pheidologdon 

 diversus), drawn from specimens supplied by Prof. August Forel. A, the largest, 

 By the intermediate, C, the smallest form. 



suitable variations cannot be selected for breeding, but only their 

 parents, the sexual animals, and these according to whether they 

 produce better workers or worse. This is how Darwin looked at the 

 matter, and his view receives support from one peculiarity in the 

 composition of these animal colonies, whose significance becomes 

 apparent in relation to this problem. It has long been known that 

 in a bee-hive there are from 10,000 to ao,ooo workers, but only one 

 true female, the so-called queen, and the meaning of this remarkable 

 arrangement probably is, that the adaptation of the workers through 

 natural selection becomes much more easily possible, since the tvhole 

 number are the children of a single pair. It is not the individual 



II. H 



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