293 BOTANICAL GAZETTE [MARCH 
burner flame was used, the regulation of the temperature being 
made automatic by the use of a mercury thermo-regulator. A 
finger bowl containing 100 cc. of tap water stood upon the water 
bath, and the seeds, lying upon a square of loosely woven cotton 
cloth, were placed within it. By the use of such a container for 
the seeds, it was possible to remove all of the material at exactly 
the same moment. In the second method an electric incubator, 
within which stood a beaker containing 100 cc. of water, was 
found to give excellent results. An additional stove attachment 
and an electric regulator on the apparatus made it possible to 
maintain high and constant temperatures. When the tempera- 
ture in the beaker had been kept constant at the desired point 
for an hour, the seeds were dropped into the water and could 
be taken out at the end of the time intervals almost as rapidly 
as in the former method. The whole temperature range given 
in the table below was covered according to the second method, 
while the effect of temperatures between 60° and 70° C. was inves- 
tigated according to the first. The variations in temperature 
amounted to 022 C. for the temperatures above 60° C., and 0°3 C. 
for all temperatures below and including 60° C. The time during 
which these variations lasted, however, was relatively so short 
that this source of error may be disregarded. 
For observing the progress of germination the seeds were placed 
upon moist filter paper so arranged in a finger bowl containing 
about 20 cc. of water that the surface of the paper was continu- 
ally moist without any appreciable amount of water surrounding 
the seeds. In many cases the paper was perforated and the 
seeds, proximal end downward, were lightly pushed into the 
openings. A difficulty was encountered in connection with the 
molds Rhizopus nigricans and Penicillium crustaceum, which 
usually attacked the seeds on the third or fourth day. Any 
seeds that were evidently dead and decomposing were at once 
discarded as soon as the mold appeared, and any others affected 
but showing signs of germination were carefully watched and 
kept free from mold by wiping with sterilized lens paper. In : 
cases the material was kept at room temperature and in partial 
darkness. 
