422 UTRICULARIA NEGLECTA. Cuar. XVIL 
surfaces. The glands are variously affected by absorp- 
tion; they often become of a brown colour; sometimes 
they contain very fine granules, or moderately sized 
grains, or irregularly aggregated little masses ; some- 
times the nuclei appear to have increased in size; the 
primordial utricles are generally more or less shrunk 
and sometimes ruptured. Exactly the same changes 
may be observed in the glands of plants growing 
and flourishing in foul water. The spherical glands 
are generally affected rather differently from the 
oblong and two-armed ones. The former do not so 
commonly become brown, and are acted on more 
slowly. We may therefore infer that they differ some- 
what in their natural functions. 
It is remarkable how unequally the glands on the 
bladders on the same branch, and even the glands 
of the same kind on the same bladder, are affected by 
the foul water in which the plants have grown, and by 
the solutions which were employed. In the former 
case I presume that this is due either to little currents 
bringing matter to some glands and not to others, or 
to unknown differences in their constitution. When 
the glands on the same bladder are differently affected 
by a solution, we may suspect that some of them 
had previously absorbed a small amount of matter 
from the water. However this may be, we have 
seen that the glands 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 
