3° 2 Journal of Agricultural Research voi. vn-m , no. 5 
The temperature alternation giving best results in these tests (20° to 
30° C.) is almost identical in mean temperature with that (21 0 for 8 hours 
and 28° for 16 hours) which Vanha (21) in his careful and thorough 
investigation found most advantageous for the germination of this 
species. Brown (i) also recommended an alternation between 20° and 
30° for the germination of seeds of this species. 
CELERY 
Figure 4 shows that celery seed germinated almost as completely at 
nearly constant low temperatures as with temperature alternations, 
though it germinated more slowly. However, as the germination tem¬ 
perature increased a relatively wide alternation (io° C.) became impera¬ 
tive and still wider alternation [15 0 or 20°) did no harm. As with Ken- 
