Onap. XV. ON THE DROSERACE. 36) 
tentacles of Drosera, with their glands aborted, but then 
sensitiveness retained. Under this point of view we 
should bear in mind that the summits of the tentacles 
of Drosera, close beneath the glands, are sensitive. 
The three most remarkable characters possessed by 
the several members of the Droseracez consist in the 
leaves of some having the power of movement when 
excited, in their glands secreting a fluid which digests 
animal matter, and in their absorption of the digested 
matter. Can any light be thrown on the steps 
by which these remarkable powers were gradually 
acquired ? 
As the walls of the cells are necessarily permeable 
to fluids, in order to allow the glands to secrete, it is 
not surprising that they should readily allow fluids to 
pass inwards; and this inward passage would deserve 
to be called an act of absorption, if the fluids com- 
bined with the contents of the glands. Judging from 
the evidence above given, the secreting glands of 
many other plants can absorb salts of ammonia, of 
which they must receive small quantities from the rain. 
This is the case with two species of Saxifraga, and the 
glands of one of them apparently absorb matter from 
captured insects, and certainly from an infusion of raw 
meat. There is, therefore, nothing anomalous in the 
Droserace having acquired the power of absorption 
in a much more highly developed degree. 
It is a far more remarkable problem how the 
members of this family, and Pinguicula, and, as Dr. 
Hooker has recently shown, Nepenthes, could all have 
acquired the power of secreting a fluid which dis- 
solves or digests animal matter. The six genera of 
the Droseracee have probably inherited this power 
from a common progenitor, but this cannot apply to 
