276 MR. C. DARWIN ON THE ACTION OF 
though slowly. In many, but not in all, of the cells of this leaf 
the grains of chlorophyll were still quite distinct. The several 
leaves were left both in the stronger and weaker solutions for 
48 hours; and this caused the yellow spheres and masses to dis- 
integrate into brownish granular matter. In this respect the 
aggregated masses in Drosophyllum differ from those in Drosera 
and Dionea. Leaves were also left for 24 and 48 hours in an 
infusion of raw meat; but no yellow aggregated masses were 
thus produced, and the grains of chlorophyll remained perfectly 
distinct. This singular difference in the action of the infusion 
of raw meat on the tentacles, as compared with those of Drosera, 
may perhaps be accounted for by their serving in Drosophyllum 
almost exclusively for the secretion of the viscid fluid by which 
insects are captured—the power of digestion and of absorption 
being chiefly confined, as I have explained in my ‘ Insectivorous 
Plants’ (pp. 332-342), to the minute sessile glands on the disks 
of the leaves. 
As in the three foregoing genera the grains of chlorophyll 
tend to aggregate into moving masses under the long-continued 
influence of a weak solution of carbonate of ammonia, I thought 
that the grains would probably be similarly acted on in all in- 
sectivorous plants; but this did not prove to be the case. The 
immersion of leaves of the common Pinguicula in a solution of 
the ammonia and in an infusion of raw meat did not cause any 
aggregation of the chlorophyll-grains, though numerous trans- 
parent spheres were formed within the glandular hairs. Again, 
the immersion in carbonate of ammonia of pieces of young and 
old pitchers of a Nepenthes (garden hybrid variety) caused the 
appearance of innumerable more or less confluent spheres of 
various sizes in the glands on the inner surface of the pitcher 
and in the exterior epidermal cells. These were formed of trans- 
lucent matter, either almost colourless or of a brown, orange, 
purple, or greenish tint; but the grains of chlorophyll were not 
acted on. 
Sarracenia purpurea.— The pitehers of this plant are evidently 
adapted for catching and drowning insects; but whether they 
ean digest them, or may have the power of absorbing matter 
from their decaying remains, is doubtful *. Many observations 
* See an interesting account of the inner epidermal cells by A. Batalin, 
“Ueber die Function der Epidermis in den Schlauchen von Sarracenia &o." 
1880. Reprinted from ‘Acta Horti Petropolitani,’ t. vii. (1880). 
