96 ‘  DROSERA ROTUNDIFOLIA. Cuap. VI. 
process of digestion now commenced, so that within 48 hrs. from 
the time when the acid was given the four cubes were not only 
completely dissolved, but much of the liquefied albumen was 
absorbed. 
Experiment 11—Two cubes of albumen (25 of an inch, or 
‘635 mm.) were placed on two leaves, and were treated with 
alkalies as inthe last experiment, and with the same result; 
for after 22 hrs. they had their angles perfectly sharp, showing 
that the digestive process had been completely arrested. I then 
wished to ascertain what would be the effect of using stronger 
hydrochloric acid ; so I added minute drops of the strength of 
1 per cent. This proved rather too strong, for after 48 hrs. 
from the time when the acid was added one cube was still 
almost perfect, and the other only very slightly rounded, and 
both were stained slightly pink. This latter fact shows that the 
leaves were injured,* for during the normal process of digestion 
the albumen is not thus coloured, and we can thus understand 
why the cubes were not dissolved. 
From these experiments we clearly see that the 
secretion has the power of dissolving albumen, and 
we further see that if an alkali is added, the process of 
digestion is stopped, but immediately recommences as 
soon as the alkali is neutralised by weak hydrochloric 
acid. Even if J had tried no other experiments than 
these, they would have almost sufficed to prove that 
the glands of Drosera secrete some ferment analo- 
gous to pepsin, which in presence of an acid gives 
to the secretion its power of dissolving albuminous 
compounds. 
Splinters of clean glass were scattered on a large 
number of leaves, and these became moderately in- 
flected. They were cut off and divided into three 
lots; two of them, after being left for some time in 
a little distilled water, were strained, and some dis- 
* Sachs remarks (‘Traité de agents, allow all their colouring 
Bot.’ 1874, p. 774), that cells matter to escape into the sur 
which are killed by freezing, by rounding water. 
too great heat, or by chemical 
