ey eee 
Cuar. XVII.] SUMMARY ON ABSORPTION. 341 
on the same leaf of Drosera are sometimes very unequally 
affected, more especially when exposed to certain vapours. 
If glands which have already become brown, with their 
primordial utricles shrunk, are irrigated with one of the 
effective solutions, they are not acted on, or only slightly and 
slowly. If, however, a gland contains merely a few coarse 
granules, this does not prevent a solution from acting. I 
have never seen any appearance making it probable that 
glands which have been strongly affected by absorbing matter 
of any kind are capable of recovering their pristine, colour- 
less, and homogeneous condition, and of regaining the power of 
absorbing. 
From the nature of the solutions which were tried, I 
presume that nitrogen is absorbed by the glands; but the 
modified, brownish, more or less shrunk, and aggregated 
contents of the oblong glands were never seen by me or by 
my son to undergo those spontaneous changes of form 
characteristic of protoplasm. On the other hand, the contents 
of the larger spherical glands often separated into small 
hyaline globules or irregularly shaped masses, which changed 
their forms very slowly and ultimately coalesced, forming a 
central shrunken mass. Whatever may be the nature of the 
contents of the several kinds of glands, after they have been 
acted on by foul water or by one of the nitrogenous solutions, 
it is probable that the matter thus generated is of service to 
the plant, and is ultimately transferred to other parts. 
The glands apparently absorb more quickly than do the 
quadrifid and bifid processes; and on the view above main- 
tained, namely that they absorb matter from putrid water 
occasionally emitted from the bladders, they ought to act 
more quickly than the processes; as these latter remain in 
permanent contact with captured and decaying animals. 
Finally, the conclusion to which we are led by the fore- 
going experiments and observations is that the bladders have 
no power of digesting animal matter, though it appears that 
the quadrifids are somewhat affected by a fresh infusion of 
raw meat. It is certain that the processes within the 
bladders, and the glands outside, absorb matter from salts of 
ammonia, from a putrid infusion of raw meat, and from urea, 
Lhe glands apparently are acted on more strongly by a 
solution of urea, and less strongly by an infusion of raw 
meat, than are the processes. The case of urea is particularly 
interesting, because we have seen that it produces no effect 
