CARNIVOROUS PLANTS WITH ADHESIVE APPARATUS. 157 
with the nitrogenous compounds dissolved therein, is absorbed without delay. 
Hollows of this kind occurring in foliage-leaves only differ from those above 
described as developed on sarracenias in being destitute of special contrivances for 
decoying animals into the traps, and for rendering their escape from the latter 
impossible. It cannot be denied that through forms of this kind a gradual 
transition has been proved to exist between plants which absorb nearly pure water 
by means of their foliage-leaves and those which capture animals. And, further, 
amongst the latter we find all gradations of mechanism from Drosophyllwm and 
the Primulas with their epiphyllous secretory glands up to the Fly-trap (Dione), 
which exhibits the most complex apparatus of all for capturing and digesting prey, 
and in which division of labour is carried to its highest development by the com- 
munities of cells constituting the foliage-leaves. 
It is not surprising that the first apparatus for capturing and digesting insects 
to be noticed, to have its functions recognized and to be described, was that of 
Dionea. But it strikes one as all the more strange that of late the question has 
repeatedly been mooted in the very case of Dionca, as to whether the capture and 
digestion of insects is not injurious instead of beneficial to these plants. Gardeners, 
who have cultivated Dionwa in greenhouses, have made the observation that 
individuals protected from the visits of insects thrived at least as well as those 
whose leaves were covered with bits of meat, &e., or, to employ the usual phrase, 
were fed with meat. It has also been found that a leaf cannot stand more than 
three meals; indeed, it often happens that even after the first occasion of digesting 
a bit of meat, the leaf concerned shows signs of having been injured by the 
repast. That is to say, a long time elapses before leaves which have digested 
a largish albuminoid mass regain their normal irritability; and often they wither 
and die. If cheese is placed on Dion«a, it is true the leaf closes over it, and there 
is a commencement of the process of solution, but before this is accomplished the 
leaf turns brown and perishes. Yet if Dionwa were obliged to lose a leaf after 
every meal, the result would be very disadvantageous. 
As against these considerations, we have first of all to remark that the 
absorption of nutriment takes place in nature in a manner differing materially from 
the phenomenon in greenhouses. A leaf of Dionea in the wild state is protected 
against the possibility of receiving too plentiful a dose of albuminoid substances at 
a time. Insects so large as not to allow the lobes to close together over them slip 
out again, and only small ones are caught and retained. When, in the latter case, 
one deducts the chitinous coat, and in general all parts not susceptible of being 
digested, such a small quantity of albuminoid compounds is left that, compared with 
it, the little cubes of meat used in the“experiments made in greenhouses must be 
looked upon as an exceedingly sumptuous repast. But that so small an amount of 
nitrogenous food as is to be derived from a tiny captured insect does not act 
injuriously, follows from the fact that dionwas growing wild flourish excellently, 
and do not exhibit the brown discoloration of the leaves which is caused in a 
greenhouse by placing bits of cheese upon them. If the absorption of nitrogenous 
