1876.] New Phase of Plant-Life. 11 
Elaters , two Chrysomelas, one a Curculio, one a thick and 
broad spider, one a Scolopendra, and one a fly. Thus the 
plant may be said to prey upon apterous species, or upon 
such as, though winged, cannot instantly take flight when 
the lobes of the leaf close. Very small inserts may escape 
between the spikes, and some very strong species may 
succeed in forcing their way out. This was once observed 
by Mrs. Treat in the case of a species of rosechafer 
( Macrodactylus subspinosus) . As regards the range of its 
digestive powers, Dioncea corresponds very closely with 
Drosera . As regards the movement of the leaves, we 
cannot omit to mention Dr. Burdon Sanderson’s beautiful 
discovery that there is a normal eleCtric current in the blade 
of the leaf and in its foot-stalk ; when the leaf is irritated, 
the current is disturbed in the same manner as takes place 
during the contraction of the muscles of an animal. It is 
noteworthy that Dioncea is a less prosperous member of the 
plant world than is Drosera. Whilst the latter has been 
developed into about 100 species ranging in the Eastern 
Continent from the ArCtic regions to South Africa, India, 
and Australia, and in the Western from Canada to Tierra 
del Fuego, Dioncea forms only a single species, limited to 
one district in Carolina. 
Our attention is next drawn to the Aldrovandas, small 
aquatic plants allied to the Droseracese, and capable of 
securing and preying upon living creatures. Here also we 
find the secretion of a true digestive fluid and subsequent 
absorption of the matter thus digested. But in these 
species we find processes which appear also to absorb 
excrementitious and putrescent animal matter. “ If this 
view is corredt,” says Mr. Darwin, “ we have the remarkable 
case of different parts of the same leaf serving for very 
different purposes, one part for true digestion, and another 
for the absorption of decayed animal matter. We can thus 
also understand how, by the gradual loss of either power, a 
plant might be gradually adapted for the one function to the 
exclusion of the other.” In the genera Utricularia , Genlisea , 
and their allies, we find, accordingly, that though animals 
are entrapped, they are not digested, but allowed to pass 
into putrefaction, upon the products of which the plant is 
nourished. Mr. Darwin’s final summary may be usefully 
quoted in full : — • 
“ Ordinary plants of the higher classes procure the 
requisite inorganic elements from the soil by means of their 
roots, and absorb carbonic acid from the atmosphere by 
means of their leaves and stems. But we have seen that 
