280 BOTANICAL GAZETTE [APRIL 
Enzymes 
The favorable effects of light on the germination of seeds of 
Veronica peregrina in the early work of HEINRICHER (19) was 
referred to its effect upon chemical actions connected with the 
reactivation of reserve materials, and later (21) to its effect upon 
enzyme activity in the production and digestion of stored foods. 
He (22) referred the retarding effect of light on the germination of 
seeds of Phacelia tanacetifolia to its photochemical action on 
reserve materials, and assumed that the effectiveness of the fat 
splitting lipase was favored by the increased acid formation in 
darkness, while the irrefrangible light or the rays of the first half 
of the spectrum interfered, neutralizing the acid and ae. 
checking the decomposition of fat. 
It seemed possible that enzymes of some kind might be active 
agents, and light the stimulus or trigger in the germination of 
certain seeds. Just what kinds of enzymes function most in the 
germination of light-sensitive seeds has not been shown. To 
determine whether proteolytic enzymes were the important enzymes 
for the seeds, as LEHMANN and OTTENWALDER (36) believed for 
seed of Epilobium hirsutum, seeds of Verbascum Thapsus and 
Nicotiana Tabacum were incubated in light and darkness 
respectively for four days and promptly ground in a little 50 per 
cent water solution of glycerine to which a crystal of thymol had 
been added. Small drops of extract from each kind of seed were 
put on nutrient gelatin according to the method of GrEsEN (16). 
After 30 minutes the extract was taken up with soft filter 
paper. There were very shallow pits formed where the extracts 
incubated in light had been. There were also shallow pits formed 
on the gelatin where the extract incubated in darkness had been. 
In fact, the pits produced by the extract germinated in darkness 
were deeper than those produced by the extract incubated in light. 
To verify these observations, the tests were repeated after allowing 
a more complete extraction of the enzyme. The extracts of seeds 
incubated in light were put in light, and the extracts of seeds 
incubated in darkness were put in darkness. The following day 
the same tests were repeated. Extracts from each lot of seeds 
were tested for their action by putting loopfuls on gelatin. After 
30 minutes the extracts were removed separately, when it was 
