384 PINGUICULA VULGARIS. Cuar. XVI 
acid secretion, out were not quite dissolved after two days; and 
the glands thev began to dry. Nor could their complete dis- 
solution have been expected from what we have seen with 
Drosera. 
(11) Minute drops of skimmed milé were placed on a leaf, and 
these caused the glands to secrete freely. After 3 hrs. the milk 
was found curdled, and after 23 hrs. the curds were dissolved, 
On placing the now clear drops under the microscope, nothing 
sould be detected except some oil-globules, ‘Tne secretion, 
therefore, dissolves fresh casein. 
(12) Two fragments of a leaf were immersed for 17 hrs., 
each in a drachm of a solution of curbonate of ummonia, of two 
strengths, namely of one part to 487 and 218 of water. The 
glands of the longer and shorter hairs were then examined, and 
their contents found aggregated into granular matter of a 
brownish-green colour. These granular masses were seen by 
ny son slowly to change their forms, and no doubt consisted of 
protoplasm. The aggregation was more strongly pronounced, 
and the movements of the protoplasm more rapid, within the 
glands subjected to the stronger solution than in the others. 
‘The experiment was repeated with the same result; and on 
this occasion I observed that the protoplasm had shrunk a little 
from the walls of the single elongated cells forming the pedicels. 
In order to observe the process of aggregation, a narrow strip 
of leaf was laid edgeways under the microscope, and the glands 
were seen to be quite transparent; a little of the stronger solu- 
tion (viz. one part to 218 of water) was now added under the 
covering glass; after an hour or two the glands contained very 
fine granular matter, which slowly became coarsely granular 
and slightly opaque; but even after 5 hrs. not as yet of a 
brownish tint. By this time a few rather large, transparent, 
globular masses appeared within the upper ends of the pedicels, 
and the protoplasm lining their walls had shrunk a little. It 
is thus evident that the glands of Pinguicula absorb carbonate 
of ammonia; but they do nct absorb it, or are not acted on by 
it, nearly so quickly as those of Drosera. - 
(13) Little masses of the orange-coloured pollen of the 
common pea, placed on several leaves, excited the glands to 
secrete freely. Even a very few grains which accidentally fell 
on a single gland caused the drop surrounding it to increase so 
much in size, in 28 hrs., as to be manifestly larger than the 
drops on the adjoining glands. Grains subjected to the secretion 
for 48 hrs. did not emit their tubes; they were quite dis- 
coloured, and seemed to contain less matter than before; that 
