298 PINGUICULA VULGARIS. (Cuar. XVI. 
of 18 inches; but the fluid in this case was secreted by a 
gland which had been excited. The edge of the leaf is 
translucent, and does not bear any glands; and here the 
spiral vessels, proceeding from the midrib, terminate in cells 
marked by a spiral line, somewhat like those within the 
glands of Drosera. 
The roots are short. Three plants were dug up in North 
Wales on June 20, and carefully washed ; each bore five or 
six unbranched roots, the longest of which was only 1+2 of 
an inch. ‘Two rather young plants were examined on 
September 28; these had a greater number of roots, namely 
eight and eighteen, all under 1 inch in length, and very little 
branched. 
I was led to investigate the habits of this plant by being 
told by Mr. W. Marshall that on the mountains of Cumber- 
land many insects adhere to the leaves. 
A friend sent me on June 23 thirty-nine leaves from North Wales, 
which were selected owing to objects of some kind adhering to them. 
Of these leaves, thirty-two had caught 142 insects, or on an average 
4'4 per leaf, minute fragments of insects not being included. Besides 
the insects, small leaves belonging to four different kinds of plants, 
those of Erica tetralix being much the commonest, and three minute 
seedling plants, blown by the wind, adhered to nineteen of the leaves. 
One had caught as many as ten leaves of the Erica. Seeds or fruits, 
commonly of Carex and one of Juncus, besides bits of moss and other 
rubbish, likewise adhered to six of the thirty-nine leaves. The same 
friend, on June 27, collected nine plants bearing seventy-four leaves, 
and all of these, with the exception of three young leaves, had caught 
insects; thirty insects were counted on one leaf, eighteen on a second, 
and sixteen on a third. Another friend examined on August 22 some 
plants in Donegal, Ireland, and found insects on 70 out of 157 leaves; 
fifteen of these leaves were sent me, each having caught on an average 
2°4 insects. To nine of them, leaves (mostly of Erica 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 vulgaris. In Cumberland, Mr. 
Marshall, on September 3, carefully examined for me ten plants 
bearing eighty leaves; and on sixty-three of these (i.e. on 79 per 
cent.) he found insects, 143 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 
