38 RADIOOENESIS IN EVOLUTION. 



developed. Thus certain sea-weeds {Macrocjj.slis) are as 

 large as forest trees, and the cell structure of Diatoms and 

 Desmids "" must be regarded as more highly organized than 

 many small annual composites." The author asks which 

 group has reached the highest point — " is it the Aristolo- 

 chiacea\ Cannacea\ Magnoliacea'. the Orchids, the Com- 

 posites, the Ranunculacea\ the Papilionacea^ or the Pome- 

 granates ^ . . . Like the theory of adaptability, that of 

 progressive transformations froni inherent forces fails to 

 give us a reasonable explanation of the variations which 

 plants have undergone in jirocess of time."* 



Cope used the term "" expression-point " for the fixed 

 and definite acquisition of some new character which has 

 marked a ne\\ advance in the gradation of life. And 

 Smith Woodward adds that this "" seems to have rendered 

 possible, or. at least, been an essential accompaniment of 

 a fresh outburst of developmental energy." -The same writer 

 says : ■" Palaeontology, indeed, is clearly in favour of the 

 theory of discontinuous mutation, or advance by sudden 

 changes, which has lately received so much support from 

 the botanical experiments of H. de Vries."t 



Dendy in his lucid work. " Outlines of Evolutionary 

 Biology, "J states that the branching of the phylogenetic 

 tree, representing the evolution of life, has been monopodial 

 rather than dichotomous or polychotomous. But here we 

 think there is a great deal of opposing evidence. Latterly 

 there has been accumulated palaeontological material 

 which points to a multiple origin of many types. It seems 

 not unlikely that even man himself arose radially from a 

 numl)er of mutable anthropoid forms. The authority of 

 Arthur Keith** may be quoted to the effect that certain 

 fossil crania, amongst which may be included the famous 

 Piltdown skull, Eoanfhropus Dawsoni, and Neanderthal 

 types, represent distinct and fextinct types of humanitj' and 

 not forms ancestral to modern man. And there is no 

 arbitrary reason why these distinct genera and species 



*V()1. II., p. 599. 



fAnu. & Mag. of Nat. His., Vol. 18, 1906, p. 316. 

 JOp. cit., p. 230. 



**" Bedrock," January, 191-1. (In the .same journal, April, 1914, 

 G. Elliot Smith strongly dissents from this view). 



