1921] GARDNER—GERMINATION 281 
found that well defined pits had been formed in the gelatin. More- 
over, where the extract was left on the gelatin for 24 hours, 
the pits became quite deep, even though there was abundance of 
thymol to inhibit bacterial action. These results were confirmed 
by the method of Griiss (17). 
Since the activity on gelatin of enzymes of seeds incubated 
in darkness was equal to or greater than that of seeds incubated 
in light, the favorable effect of light on germination of Nicotiana 
Tabacum and Verbascum Thapsus cannot be referred to activation 
of proteolytic enzymes. 
It has already been seen that starch does not occur in the 
embryos of any of these light-sensitive seeds, and that it occurs 
only in the endosperms of Daucus Carota and Rumex crispus. 
From these facts it is evident that hydrolysis of contained starch 
can increase the hydrogen ion of the embryos little if any. It has 
been seen that proteolytic enzymes develop equally well in darkness 
and light in these seeds, hence they can be rejected as important 
factors in determining light germination. Also, incubation in 
light does result in increased acidity of embryos over those incu- 
bated in darkness. 
It has been shown that the embryos of these seeds all contain 
fatty substances. The generally accepted method of demonstrating 
the presence of lipolytic enzymes is by the increase of acidity in 
the presence of fats. Inasmuch as development of acidity in the 
presence of light and fatty substance has been clearly demonstrated, 
it may be concluded that light activates the lipolytic enzyme to 
split the fatty substance to yield an acid. The results obtained 
with enzymes of seeds of Verbascum Thapsus and Nicotiana Tabacum 
do not support HEtyricHER’s (22) assumption that light inhibited 
the action of lipase in seeds of Phacelia tanacetifolia. On the 
other hand, the results indicate that light favored the action of 
lipase in seeds of Verbascum Thapsus and Nicotiana Tabacum. 
Discussion 
COAT EFFECTS 
The light relation of seeds of Rumex crispus is largely one 
affecting the coats, as is indicated by increased germination in 
darkness following abrasion and removal of coats, treatment with 
