300 Journal of Agricultural Research voi. xxm, no. 5 
of the actual mean temperature seems to predominate, except with 
the wide alternation 20° to 35 0 , over the influence of alternations as 
contrasted with constant temperatures; and it is only in the later days 
of^the tests that some of the alternations prove their superiority. From 
the standpoint of rapidity of germination, alternations with 30° are 
preferable to alternations with 35 0 as the higher temperature. 
