BY HEBEK A. LONGMAN. 11 



the head to the other . . . may be attributed to the 

 habit, no doubt beneficial to the individual and to the 

 species, of endeavouring to look upwards with both eyes, 

 whilst resting on one side at the l)ottom. . . . We 

 should keep in mind as I have before insisted, that the 

 inherited effects of the increased use of j)(i^'ts and perhaps 

 of their disuse,* will be strengthened b}- natural selection. 

 Por all spontaneous variations in the right direction will 

 thus be preserved : as will those individuals which inherit 

 in the highest degree the effects of the increased and 

 beneficial use of any part. How much to attribute in each 

 particular case to the effects of use, and how much to 

 natural selection, it seems impossible to decide." 



There can be no question that the ability of the young- 

 flat-fish to move the lower eye to the position seen in the 

 mature fish is now part of the inherited outfit of the 

 organism, enabling it to respond to the stimuli of environ- 

 ment. It does not appear as a novel character in each 

 individual. The result, however, depends on favourable 

 circumstances. To quote Alexander Agassiz on flounders : 

 '■ There are right-sided and left-sided species, and it is 

 curious to note that nature does not furnish the individual 

 with an unfailing instinct as to A\hich side it is fitting to 

 lie down on. In one case, out of fifteen individuals, no 

 less than eight lay down on the wrong side, and perished 

 of what appeared to be a sort of l)ra.in trouble." 'f 



In his logical enumeration of " four different 

 complexes of causes " underlying variation of type, H. F. 

 Osborn,J the Avell-known American scientist, regards 

 environment as a powerfid factor in evolution, but 

 eimphasises the energy of the organism. Obviously his 

 \ lews cannot be summarised in this address. (We note 

 parenthetically an important point made by Osborn on the 

 origin of life itself by regarding it as '" a continuation of 

 the evolutionary process rather than an exception to the 

 rest of the cosmos . . . ." A twentieth century 



* Italics ours. 



f.Life of AlexaiuUr Agassiz, 1913, p. loll. 



4:H. F. O.sborn : The Origin and Evolution of Life. 1S18 etc. 



