242 DIONÆA MUSCIPULA. [Cuap. XIII. 
likewise shown by the very different lengths of time (as we 
shall presently see) during which the lobes remain closed 
over insects and other bodies yielding soluble nitrogenous 
matter, and over such as do not yield any. But there is 
direct evidence of absorption in the condition of the glands 
which have remained for some time in contact with animal 
matter. Thus bits of meat and crushed insects were several 
times placed on glands, and these were compared after some 
hours with other glands from distant parts of the same leaf. 
The latter showed not a trace of aggregation, whereas those 
which had been in contact with the animal matter were well 
ageregated. Aggregation may be seen to occur very quickly 
if a piece ofa leaf is immersed in a weak solution of carbonate 
of ammonia. Again, small cubes of albumen and gelatine 
were left for eight days on a leaf, which was then cut open. 
The whole surface was bathed with acid secretion, and every 
cell in the many glands which were examined had its 
contents aggregated in a beautiful manner into dark or pale 
purple, or colourless globular masses of protoplasm. These 
underwent incessant slow changes of forms; sometimes 
separating from one another and then reuniting, exactly as 
in the cells of Drosera, Boiling water makes the contents 
of the gland-cells white and opaque, but not so purely white 
and porcelain-like as in the case of Drosera. How living 
insects, when naturally caught, excite the glands to secrete 
so quickly as they do, I know not; but I suppose that the 
great pressure to which they are subjected forces a little 
excretion from either extremity of their bodies, and we have 
seen that an extremely small amount of nitrogenous matter 
is sufficient to excite the glands. 
Before passing on to the subject of digestion, I may state 
that I endeavoured to discover, with no success, the functions 
of the minute octofid processes with which the leaves are 
studded. From facts hereafter to be given in the chapters 
on Aldrovanda and Utricularia, it seemed probable that they 
served to absorb decayed matter left by the captured insects ;. 
but their position on the backs of the leaves and on the 
footstalks rendered this almost impossible. Nevertheless, 
leaves were immersed in a solution of one part of urea to 437 
of water, and after 24 hrs. the orange layer of protoplasm 
within the arms of these processes did not appear more 
aggregated than in other specimens kept in water. I then 
tried suspending a leaf in a bottle over an excessively putrid 
