370 PINGUICULA VULGARIS. Cuay. XVI 
these leaves were sent me, each having caught on an average 2°4 
insects. To nine of them, leaves (mostly of Krica tetralix) ad- 
hered ; but they had been specially selected on this latter account. 
I may add that early in August my son found leaves of this same 
Erica and the fruits of a Carex on the leaves of a Pinguicula 
in Switzerland, probably Pinguicula alpina ; some insects, but no 
great number, also adhered to the leaves of this plant, which 
had much better developed roots than those of Pinguicula vul- 
garis, In Cumberland, Mr. Marshall, on September 38, carefully 
examined for me ten plants bearing eighty leaves; and on sixty- 
three of these (i.e. on 79 per cent.) he found insects, 148 in 
number; so that each leaf had on an average 2°27 insects. A 
few days later he sent me some plants with sixteen seeds or 
fruits adhering to fourteen leaves. There was a seed on three 
leaves on the same plant. The sixteen seeds belonged to nine 
different kinds, which could not be recognised, excepting one 
of Ranunculus, and several belonging to three or four distinct 
species of Carex. It appears that fewer insects are caught late 
in the year than earlier; thus in Cumberland from twenty to 
twenty-four insects were observed in the middle of July on 
several leaves, whereas in the beginning of September the 
average number was only 2:27. Most of the insects, in all the 
foregoing cases, were Diptera, but with many minute Hyme- 
noptera, including some ants, a few small Coleoptera, larve, 
spiders, and even small moths. 
We thus see that numerous insects and other objects 
are caught by the viscid leaves; but we have no right 
to infer from this fact that the habit is beneficial to 
the plant, any more than in the before given case of 
the Mirabilis, or of the horse-chestnut. But it will pre- 
sently be seen that dead insects and other nitrogenous 
bodies excite the glands to increased secretion ; and 
that the secretion then becomes acid and has the 
power of digesting animal substances, such as albumen, 
fibrin, &c. Moreover, the dissolved nitrogenous matter 
is absorbed by the glands, as shown by their limpid 
contents being aggregated into slowly moving gra- 
nular masses of protoplasm. The same results follow 
when insects are naturally captured, and as the plant 
lives in poor soil and has small roots, there can be no 
