In the months of May and June, these swellings may be found in great plenty. They are mostly seen upon young cattle, and as a general rule are situated close to the spine. So common indeed are they, that out of a whole farm-stock of cattle I have seen almost every cow under the age of four years attacked by the Breeze Fly, and counted from two or three to twelve or fourteen upon a single animal. It is said that as many as forty have been detected upon a single cow, but such an event has not come within my own observation.

The swellings caused by the Breeze Fly are called Wurbles, or Wornils, and can be easily detected by passing the hand along the back. Strangely enough, the cow does not appear to feel any pain from the presence of these large parasites, nor does she suffer in condition from them, although it would seem that they must keep up a continual drain upon the system. Indeed, some experienced persons have thought that, instead of being injurious, they are absolutely beneficial.

When the grub has reached its full development, it pushes itself backwards out of the gall, and falls to the ground, into which it burrows. Presently, the skin of the pupa becomes separated from that of the larva, and the latter dies, and becomes the habitation in which the pupa lives. The head portion of the skin is so formed that it flattens when dry, and can easily be pushed off, like the lid of a box, permitting the perfect fly to escape. Even when the insect is still in its pupal condition this lid can be removed, so that the pupa can be seen within its curious habitation. I may mention here that insects which are thus covered while in their pupal state, so as to show no traces of the creature within, are said to undergo a coarctate" metamorphosis. Nearly all the diptera are examples of the coarctate insects.

BEFORE we close the subject of parasites, it will be needful to give a brief account of one or two parasitic insects which possess points of peculiar interest in the habitations which they make, or in the places wherein they find their abode.

One of these insects is a rather pretty beetle, termed Clerus alvearius. In its perfect state it is innocent enough, but in its larval state it is so destructive among the hives, that all beekeepers will do well to destroy every Clerus that they can catch.

It is generally to be found on flowers, licking up their sweet juices by means of a brush-like apparatus attached to the mouth. The wing-cases of most of the species are bright red, barred or spotted with purple.

The larva is of a beautiful red, and is hatched from an egg placed in the cell occupied by the bee-grub. As soon as it is hatched, it proceeds to feed upon the bee-grub, and devours it. Unlike many insects with similar habits, it is not content with a single grub, but proceeds from cell to cell, devouring all their inhabitants. When it has eaten to the full, it conceals itself in the cell, and spins a cocoon of rather small dimensions in com parison with its own size. In process of time, it is developed into a perfect insect, and then breaks out of its cocoon and leaves the hive, secure from the bees, whose stings cannot penetrate the horny mail in which it is encased.

THERE is another beetle which is parasitic upon snails, and which, in its larval and pupal states, is only to be found within those molluscs. Its scientific name is Drilus flavescens, the latter name being given to it in honour of its yellow-tinted wing-cases, which present a pretty contrast with the black thorax. It is a little beetle, scarcely exceeding a quarter of an inch in length, and is remarkable for the beautiful comb-like antennæ of the male. As for the female, she is so unlike her mate that she has been described as a different insect. She has no pretensions to beauty, and can scarcely be recognised as a beetle, her form being that of a mere soft-bodied grub. Moreover, the size of the two sexes is notably different. The male is, as has already been observed, only about a quarter of an inch long, while the female is not far from an inch in length, and is broader than the length of her mate, antennæ included.

This curious insect lives in the body of snails, the common banded snail of our gardens being its usual prey. When it is about to change into the perfect state, it makes a curious cocoon, of a fibrous substance, which has been well likened to common tobacco, the scent as well as the form increasing the resemblance. The grub or larva of this beetle bears a very great resemblance to the perfect female, and indeed is so similar that none but an entomologist could distinguish the two creatures. It is furnished with a number of false legs, as well as with a forked appendage at the end of the tail, by which it is enabled to force its way into the body of its victims. The head is pointed, and the jaws are very powerful.

LL

CHAPTER XXVII.

BRANCH-BUILDING MAMMALIA.

The DORMOUSE in Confinement, and at Liberty-Nest of the Dormouse-Its position, materials, and dimensions Entrance to the nest-The winter treasury-The LOIRE and the LEROT-Man as a Branch-builder-Moselekatze -His conquests-Effects upon the people-Branch-houses-Their approaches.

WE now come to another division of the subject, namely, the nests that are built in branches, and adhering to the system which has been followed through the progress of the work, we shall take first the branch-building mammalia.

There are but few mammals which can be reckoned in this division, but our little island produces two of them, namely, the squirrel and the DORMOUSE (Muscardinus avellanarius). The former of these animals has been already described at page 196.

The pretty little brown-coated, white-bellied Dormouse is familiar to all who have been fond of keeping pets. There is no difficulty in preserving the animal in health, and, therefore, it is a favourite among those who like to keep animals and do not like the trouble of looking after them. It is, however, rather an uninteresting animal when kept in a cage, as it sleeps during the greater part of the day, and the sight of a round ball of brown fur is not particularly amusing.

When kept in confinement, it is obliged to make for itself a very inartificial nest, because it is deprived of proper materials and a suitable locality. It does its best with the soft hay and cotton wool which are usually provided for it, but it cannot do much with such materials. But when in a state of liberty, and able to work in its own manner, it is an admirable nest-maker. As it passes the day in sleep, it must needs have some retired domicile in which it can be hidden from the many enemies which might attack a sleeping animal.