XATURAL HISrORV XOTES 57 
In neither case is the date of observation given, but it seems possible that the 
bird has escaped destruction in Surrey only to be caught in Yorkshire. 
W. 
605. Pond Life. — In query No. 137 Mr. Millard tells us that his small 
pond is “ covered with duckweed,” and that there were “ numerous tracks across 
the surface.” By the narrowness of these tracks he supposes they must have 
been caused by small creatures swimming on the surface of the pond, and not by 
large ones. These tracks are not of necessity made by night, as Mr. Millard 
thinks; for I have seen them made by day, times without number, and also by 
all sorts of creatures that swim across our ponds. In all cases where the duck- 
weed is of sufficient density of growth, the effect, after a certain lapse of time, 
is that narrow tracts alone remain. 
In “Flowers of the Field,” Johns informs us that the “lesser duckweed” 
(Lemua minor) belongs to a class of minute floating plants, which are not 
attached to the soil, and that it is “ often so abundant as to cover the surface of 
stagnant waters, where, with the insects which it harbours, it is greedily devoured 
by ducks.” I have never seen the lesser duckweed grow in greater luxuriance 
than in a moat in my garden, when I lived in Hampshire. There were a 
number of trout in the moat, some perch and carp, and of course, newts, water 
beetles, and such like. None of the tracks were caused by these. Ducks were 
excluded from the moat, but there were moor hens, rats, water rats, and other 
creatures usually found in such situations, which go about the surface of the 
water. It was by these that the tracks were made ; and the width of the tracks 
was practically the same, irrespective of the creatures that caused them, a short 
time after the track was made. The duckweed grew so luxuriantly as at times 
to assume the thickness of a carpet ; and when any creature swam through it, it 
closed behind it, leaving only a narrow tell-tale track which remained for many 
hours. This is what happens when the crop of weed is dense ; when, however, it 
is a poor one, the track has a tendency to remain open; and then it may differ 
in width according to the size of the animal that swam along it. 
Mr. Millard’s pond no doubt had a fine crop of the “ lesser duckweed,” 
and the tracks probably were not caused by ducks, for they would soon have 
eaten the duckweed up. 
Many creatures live right under our noses that even the most observant would 
fail to notice. 
Edmund Thos. Daubeny. 
606. Mistletoe. — There is no difficulty in propagating mistletoe on the 
apple tree if a ripe berry be either placed in an incision in the 'oark, or even 
bruised and rubbed on the outside, so that the seeds adhere to it. In nine cases 
out of ten the experiment will succeed if the conditions are favourable, but if the 
plant roots freely it will probably result in the death of the apple tree in the 
course of a few years, or, at any rate, of the branch on which it has rooted, and 
then of course the death of the mistletoe follows. If the same experiment be 
tried on the oak, however, there will probably be a large proportion of failures 
to one success. 
W. 
607. Movements in the Organs of Plants.— In the first part of his 
article on this subject Mr. Bunyard speaks (p. 6 ) of the “ violet ” bringing its 
matured seedpod close to the soil to sow its seeds. This is too general. There 
are some 120 species of Viola, and of the eight (out of thirteen) British species I 
have here in my garden his statement is true of only one, V. hirla, so far as I 
have observed. Does he refer to this one or to V. odorata ? I have roots of only 
the white variety of the latter, and unfortunately they do not produce cleisto- 
gamous flowers ; but in all my other species, including cultivated violas, the pro- 
cess seems to be as follows : the capsule remains more or less hidden amongst 
the leaves until the time for scattering the seeds draws near. Then it assumes an 
upright position on its stalk, well above the leaves, and splits into three valves, 
which open out later and assume a spreading horizontal position. The shining 
seeds, arranged usually in a single row in each valve — in some species there are 
two rows in each valve — are not yet ripe, as shown by their pale colour, but this 
