314 
Journal of Agricultural Research voi. xxm, no. 5 
3. PROGRESS OP TEMPERATURE CHANGES IN RELATION TO GERMINATION: 
COMPARISON WITH FIEED TESTS 
From December, 1911, to May, 1912, germination tests were made 
with about 30 kinds of seed, mentioned on p. 322, under 11 different 
temperature alternations. 
^Kentucky bluegrass seed was tested in the Jacobson apparatus (4); 
and the other kinds were placed between blotters or on top of blotters, 
according to the size of the seeds. Fach chamber was constantly filled 
Fig. ii.—M edian section of a germinating chamber: (a), pan of water; 
( b), ledges to support seed trays; (c), seed trays (numbered from i to 
8 ); (d), thermo-regulator; (e) water jacket; (/), burner; (g), cold-water 
pipe; (h), perforated copper plate; (*) overflow pipe; ( k ), icebox; (/) 
thermometer. 
to its capacity. At the same time a study was made of the progress of 
temperature changes in several different parts of the chambers. These 
temperature records were supplemented later by a more detailed study 
of temperature changes in a much larger number of positions in chambers 
filled with moistened blotters, as when the germination tests were in 
progress, but this time without the seeds. From these records time- 
temperature curves were constructed. Before considering these curves, 
and in order to make their significance clear, it is well to introduce a 
brief description of the germinating chambers. 
