630 The American Naturalist. [August; 
bright light. The foliage of ombrophylic plants is easily 
wetted; that of ombrophobic plants is as a rule not readily 
wetted, being usually protected by bloom or some other device 
for warding off water. When ombrophobic plants are not pro- 
tected in some such manner, decay is remarkably rapid. In 
general if the leaves of a plant are readily wetted, it may be 
assumed that they are ombrophylic, but there are exceptions, 
e. g. the potato and tomato. Roots of all plants are extraordi- 
narily resistant. In most plants middle aged leaves are least 
susceptible to decay but in the potato the youngest leaves 
resist best. Old leaves lose this power of resistance. Some- 
times this resisting power is variable in different individuals 
of the same species, depending on the conditions under which 
they have been grown. Curiously, all plants of shady, damp 
places are ombrophobic, if they possess leaves which are not 
readily wetted, e. g. Impatiens. The more the parts of a leaf 
are divided the quicker the decay. The green parts of the fol- 
lowing plants are mentioned as particularly susceptible to bac- 
terial decay : Solanum tuberosum, Lycopersicum esculentum, Xer- 
anthemum annuum, Impatiens nolitangere, Chenopodium album, 
Veronica buxbaumii, Viola arvensis, and Taraxacum officinale 
(from sunny, dryplaces) Mimosa pudica, Pisonia alba. The fol- 
lowing plants were found to be very resistant: Ranunculus 
aquatilis, Lemna minor, Lysimachia nummularia, Begonia mag- 
nifica, Tradescantia zebrina, T. guianensis, Selaginella sp. (from 
green house), and Scolopendrium officinarum. Among under- 
ground organs the roots of the yellow beet proved most resist- 
ant. The author’s general conclusion from these experiments 
is best expressed in his own words: “It can now be'stated as 
highly probable that the power of ombrophilous organs to 
resist rain for months is referable chiefly to the fact that anti- 
septic substances are produced in the tissues of the organs.” 
These experiments are interesting but seem to have been per- 
formed in a rather crude way. The relative rapidity of decay 
was determined by appearance and the sense of smell and the 
organisms inducing this decay were undetermined. These 
experiments should be repeated and extended by Dr. Wiesner 
