Silken threads always arouse our suspicions. These may be seen lying on the surfaces of leaves, and passing from one leaf to another, or they may be hanging perpendicularly from the branches of trees above. In the latter case a larva may be frequently seen on the lower extremity of the fibre, swinging gently in the breeze, and, should we require it, we have only to place the open box below for its reception. Hawthorn and other trees are sometimes seen almost devoid of leaves, nearly every bit of green having been greedily devoured by a host of small larvae. In such cases we often meet with dense clusters of silk fibres that may easily be mistaken for spiders' nests. But when we look more closely into the structure we observe that we have discovered instead nests of gregarious larvae, such a large number being in each little community that the deplorable appearance of the tree is at once explained. A little farther on we meet with a sickly-looking plant in the midst of a number of flourishing individuals of the same species, and stop to make inquiries into the cause of this strange occurrence. Is it due to a poorness of the soil? No, this cannot be the case; for intermingled with its roots are those of its flourishing companions. We pluck a stunted and half-shrivelled leaf and examine it. At first we do not notice the cause of its peculiar condition; but, holding it up to the light, and looking _through_ it, we see a number of little galleries that have been eaten out of its internal soft substance, leaving the thin skin (_epidermis_) almost entirely intact. But nothing more is to be seen. Another leaf is examined in exactly the same way; and here we see the little destroyer, lying motionless in its burrow till a gentle pressure applied against it from outside causes it to wriggle along its narrow passage. This is the larva of one of the little leaf miners mentioned again on page 303. Reaching a little marshy spot we see a number of water-loving reeds, most of them beautifully green and in a flourishing condition, but here and there in their midst is a poor stunted specimen--another result of the ravages of the larvae of one or more moths. An examination of the blades reveals nothing; but on splitting open the stalk we discover some larvae that have already devoured a quantity of the internal pith, and thus endangered the life of the plant. On inspecting other similar reeds we are at first puzzled as to how the larvae could get inside the stems without damaging the outer portion; but at last we see in each one a little discoloured hole that was eaten out by the young caterpillar just after its escape from the egg. Once within the reed, it found a plentiful supply of food, and there grew at the expense of the plant without doing any further external damage save by causing a stunted growth.