142 DROSERA ROTUNDIFOLIA. Cuap. VIL 
did not bend. Two other plants were placed with 
their roots surrounded by damp moss, in half an ounce 
(14198 ml.) of a solution of one part of the carbo- 
nate to 218 of water, and were observed for 24 hrs. 
but not a single tentacle was inflected. In order to 
produce this effect, the carbonate must be absorbed 
by the glands. p 2 
The vapour produces a powerful effect on the glands, 
and induces inflection. Three plants with their roots 
in bottles, so that the surrounding air could not have 
become very humid, were placed under a bell-glass 
(holding 122 fluid ounces), together with 4 grains 
of carbonate of ammonia in a watch-glass. After an 
interval of 6 hrs. 15 m. the leaves appeared unaffected ; 
but next morning, after 20 hrs., the blackened glands 
were secreting copiously, and most of the tentacles 
were strongly inflected. These plants soon died. 
Two other plants were placed under the same bell- 
glass, together with half a grain of the carbonate, the 
air being rendered as damp as possible; and in 2 hrs. 
most of the leaves were affected, many of the glands 
being blackened and the tentacles inflected. But it is 
a curious fact that some of the closely adjoining ten- 
tacles on the same leaf, both on the dise and round 
the margins, were much, and some, apparently, not in 
the least affected. The plants were kept under the 
bell-glass for 24 hrs., but no further change ensued. 
One healthy leaf was hardly at all affected, though . 
other leaves on the same plant were much affected. 
‘On some leaves all the tentacles on one side, but not 
those on the opposite side, were inflected. I doubt 
whether this extremely unequal action can be ex- 
plained by supposing that the more active glands 
absorb all the vapour as quickly as it is generated, se 
that none is left for the others for we shall meet with 
