BY HEBER A. LONGMAN. 31 



In connection with these observations the term '" Biomet- 

 rics " is coming into popvilar usage. 



Henry F. Osborn, a well-known American writer, 

 claims that there are four inseparable and inter-associated 

 factors of evolution, viz. : Hei'edity, Ontogeny. Environ- 

 ment and Selection. The working; of these four factors 

 he elaborates under the term Tetraplasy. He defines 

 Ontogeny as the expression of heredity reaching to and 

 modified by the conditions of life, of environment and of 

 .selection, tind summarises no less than 24 ontogenic ]>ro- 

 cesses.* Here we have a much wider outlook and one 

 which is more in harmony with the complex phenomena 

 of variations. Osborn's work cannot be neglected by any 

 •careful student of Heredity. 



Thomson and Geddes have given us an attractive 

 theory of evolutionary processes which owes much of its 

 charm to the poetic feeling and literary style of the authors. 

 They write of definite variations which luanch dichotom- 

 ously, ■■ forms thrown from the rhythmic oscillation of the 

 loom of life," chiefly as the result of vegetative and repro- 

 ductive forces. Nature to them is no " gladiators' show " 

 (to use Huxley's term). They view variations as definite 

 rather than indefinite. "" with ])rogress essentially through 

 the subordination of individual struggle and development 

 to species-maintaining ends. The ideal of evolution is 

 thus no gladiators' show, but an Eden : and though 

 competition can never be wholly eliminated — the line of 

 progress is thus no straight line, but at most an asymptote — it 

 is much for our natural history to see no longer struggle, but 

 love as ■ creation's final law '." 



But with all due regard to the prestige of these able 

 wTiters. may we not see here the result of theorising too 

 much on physiological analyses of present day organisms, 

 instead of endeavouring to obtain a com])rehensive view 

 of the march of life from the past to the present. Does not 

 modern palaeontology suggest that variations have branch- 

 ed not definitely and simply but polychotomously '. The 

 key to the process has been Radiogenesis. and not Ortho- 

 genesis, even though .the latter term be much ([ualified. 



*Journ. Acad. Nat. Sci. Phil. 2nd Ser. Vol. XV, 1912. 



