WHAT EVOLUTION IS 99 



among protozoans, sponges, corals, 

 starfish, moss-animals, worms, and 

 the group of sea-squirts or tunicates, 

 but it is not known among snails, 

 clams, crustaceans, insects, or the ver- 

 tebrates. If, therefore, the inherit- 

 ance of acquired characters is a 

 feature of non-sexual reproduction 

 and the Lamarckian principles may 

 apply where this occurs, it is after 

 all a limited application and illus- 

 trates again what has already been 

 pointed out that Lamarckism at best 

 cannot be regarded as an all-inclusive 

 factor in evolution. From what has 

 been said it appears to be at best a 

 possible element in this process. 



