DIVERSE INHERITANCE. 43 



two reproductive types, both constant, it is evident 

 that these cannot both be modified in the 

 same way as the parent is modified. Many 

 parental modifications of structure and habit are 

 certainly not conveyed to neuter ants and bees ; 

 other modifications, which are not seen in the 

 parents, being conveyed instead. Many other 

 circumstances tend to show that the individual 

 and the transmissible type are independent of 

 each other so far as modifications of parts are 

 concerned. 



It may seem natural to expect the transmis- 

 sion of an enlarged muscle or a cultivated brain, 

 but, on the other hand, why should it be un- 

 reasonable to expect that a modification which 

 was non-congenital in origin should still remain 

 non-congenital ? Why should the non-transmission 

 of that which was not transmitted be surprising ? 



Mr. Spencer thinks that the non-transmission 

 of acquired modifications is incongruous with the 



