to man. The one which builds a case and is the titular chief of the clan of clothes moths-"the" clothes moth, just as one may say "the" MacIntosh-is scientifically indicated by the name Tinea pellionella. The other three do not form movable cases when in the caterpillar stage, and attack coarser stuff than fur and fine wool. One of them is known as the "tapestry moth," because its caterpillar establishes itself in old tapestry and carpets, and burrowing into these thickish materials is concealed without the aid of any self-provided tunic or case. The name Tinea is often used by entomologists in an expanded form as Tineina, to indicate the whole series of minute moths of which the genus Tinea is only one little group. Many of these moths are much smaller even than the clothes moth, and they are found in all parts of the world and in all sorts and conditions of life-in relation to trees, shrubs, and plants of all kinds. It has been estimated that there are as many as 200,000 distinctly marked different kinds of these minute creatures. The insect collectors and students who occupy themselves with the magnificent butterflies and larger moths (of which there are an enormous variety of kinds) refuse to deal with the somewhat dull-looking and almost innumerable minute moths which are classed as Micro-lepidoptera, in contrast to the Macro-lepidoptera (or big moths and butterflies). Consequently they have become the favourite study of a few enthusiasts, who are known as Micro-lepidopterists, and have a wide but not uninteresting field of exploration all to themselves. The Micro-lepidoptera include, besides the Tineina, a group of less minute though small moths, with narrow, fringed wings, amongst which are the window moth, the milk moth, the tabby moth, the meal moth, and the grease moth. Though the clothes moths. may well be described as "tiny" moths, yet the word Tinea, as applied to them, has no such origin, but is the

name given to the destructive grub by the Romans. The same word has unfortunately been applied by medical men and botanists to a vegetable parasite which causes a skin disease (ringworm) resulting in baldness. The Tinea calvans of the doctors has only this in common with the moth Tinea pellionella-that it causes hair to disappear and baldness to ensue; but the vegetable parasite attacks the hair on a living man's head, the caterpillar that on his fur coat.

BORING

XXXVIII

STONE AND WOOD BORERS

into wood is a favourite proceeding on the part of many small creatures, insects, shrimps, and ship-worms, by which they not only acquire nourishment, but at the same time penetrate more and more deeply into safe quarters and concealment. It is not surprising that it has become the necessary and regular mode of life of a host of small animals, and consequently that man who wants wood in good sound blocks and planks for his various constructions is a good deal put out by the voracity of the wood-boring community. To some extent he has given up the task of checking their proceedings, and now uses metal where he formerly used wood, but that only applies to a limited field. Wood is still the great material of rough construction, and the main substance used in fittings and furniture.

In our own country and in most parts of the world there are large grubs or caterpillars, such as those of the goat moth, three inches long and as thick as one's finger, which eat into the stems of trees and spoil the timber. The grub of the handsome moth known as the wood leopard is another of these. It attacks poplar trees, and we used to take it in numbers in the London parks and squares when I was a collector. The goat moth is specially destructive to willow trees. But there are a

very large series of smaller grubs and adult insects which injure trees or bore or devour wood already cut and dried. Among these are the saw-flies and a number of beetles, and in Sicily and the tropics there are the wonderful white ants which are not ants at all, but more like May-flies. The destruction caused by these borers and eaters of wood is increased by the fact that when they have riddled a piece of wood, moisture penetrates it, and vegetable "moulds" flourish within it and complete the break-up. Among the most destructive borers of wood are those which attack the ships and piers of wood placed by man in the sea. These are certain shell-fish, called ship-worms (Teredo), which are really peculiarly modified mussels. There is also a tiny shrimp-like creature, the Limnoria terebrans, which does enormous damage by its borings to piers of wood erected in the sea. True insects do not flourish in the sea. There are marine bivalve shell-fish which bore into clay, sandstone, chalk, and even into hard granite-like rock. They do not use jaws or teeth for this purpose, but the surface of their shells, which are sharp and spiny, and also the sand which adheres to their soft muscular bodies like emery powder to the pewter-plate of a lapidary's wheel. You may see the large and small holes made by Pholas (called also "the piddock") and other bivalve shell-fish in the clay and chalk rocks of the seashore on most parts of the English coast.

Most boring animals swallow the material which they excavate in the act of boring, just as the earth-worm swallows the soil into which it bores, and as many sandworms do, throwing out from the hind end of the body, in the form of a little coiled-up heap, a vast quantity of undigested matter which has passed through them. But many insects which swallow some of the material disengaged by their jaws remove, in addition, a large quantity which is ejected from the boring as powder, like

sawdust, and others do not swallow any of the material into which they bore. So, too, the Pholas and marineboring mussels do not swallow the material which they loosen. It is a very slow process, the boring in rock, and the fine particles rubbed away by incessant movement are carried off in the sea-water.

To some extent the marine creatures which bore in rocks seem to be helped by chemical action, since they show a preference for chalk and limestone, easily dissolved by weak acid secreted by the borer, though, clearly enough, they are not dependent on such chemical aid since we find them also boring in insoluble granite rock and shale and clay. There is one true worm-borer which perforates hard limestone pebbles and chalk rocks, so as to give them the appearance which we call "worm-eaten " when caused by another sort of worm and observed in a very different material, namely, old furniture and woodwork. At Tenby, in South Wales, the limestone pebbles on the beach are quite commonly riddled with these worm-holes, truly "worm-eaten." When they are not too abundant one can see that the holes are arranged in pairs like a figure 8, about half the size here printed. On splitting the rock or stone one finds a deeply-running U-shaped double tube excavated in the

stone.

In this the little worm lived. It is easiest to get at the worms in a fresh and living state on a coast where there are chalk-rocks and sea-washed lumps of chalk. The chalk is easy to split and cut at low tide, and then the little key-hole apertures can be broken across and the soft red worm extracted. It is a beautiful red-blooded little worm-little more than half an inch long-with two tactile horns on its head and little bristles and gills on the rings of its annulated body. It is a true "worm," like the

earth-worm, what naturalists call by the not displeasing "annelid." It seems at first sight impossible