114 The Botanical Gazette. {March, 
the time of decay, when the experiments were made in day- 
light and ina dark room. The decay set in much earlier in 
the dark, evidently due to the fact that many bacteria are ar- 
rested in their development and propagation when exposed to 
light. 
It appears from these experiments that the best way to 
form a correct judgment regarding the resistance of plant- 
organs against the influence of water is to keep them in stag- 
nant water. In these experiments the full-grown leaves were 
the first to lose their turgescence. They became soft and 
soon decayed. Fresh shoots of Lysimachia Nummularia were 
placed in the decayed liquid resulting from this experiment, 
and they kept fresh for fourteen days. Pieces of marchantia 
thallus lived about eight days. 
sixty-two days. : 
The same was the case with Begonia magnifica and various 
hot-house Selaginelle. These results show that various plants 
possess an unequal power of resistance against a continuous 
rain and the presence of water. The author believes himself 
justified in distinguishing two categories of plant-organs: the 
‘‘ombrophilous,” or such as love or rather tolerate the rain; 
the ‘‘ombrophobic,” which dread the rain. These terms are, 
of course, only to be applied to organs above ground. The 
underground roots are evidently always hydrophilous, even 19 
plants which have ombrophobic foliage, as for instance Impa- 
tiens noli-tangere. 
We might now at the first glance think that these two cat- 
egories of organs belong to plants which are limited to dis- 
tinct localities, say to dry or moist places, and that the 
ombrophilous foliage should characterize the hygrophytes and 
the ombrophobic the xerophytes. But this conclusion is not 
a valid one since there are some plants whose foliage is om- 
brophobic, and yet which can not be considered as xerophytes, 
as for instance Solanum tuberosum. So too there are hygro- 
phytes which are decidedly ombrophobic, like Impatiens noli- 
tangere. 
