2. THE BREAD-CRUMB SPONGE. 3. THE GRANTIA SPONGE. 4. FORAMINIFERA.] But I hardly think that anybody, on seeing it for the first time, would take it to be a sponge at all. For it is not in the least like a bath sponge. It is just a kind of fleshy crust, sometimes greenish in colour and sometimes yellow, which grows round the stems of sea-weed, or covers the surfaces of rocks and stones. And the odd thing about it is that when it clings to sea-weeds its surface is quite smooth, with a number of large holes in it, but that when it grows on rocks it is covered all over with little projections which look just like the craters of volcanoes. It is rather difficult to describe the animal which lives in the sponge, for it really consists of a large number of tiny animals all joined together in one common mass, very much like the polyps of the sea finger. But they are so very small that unless you examine them by means of a good strong microscope they only look like a mass of brownish jelly. These little creatures obtain their food in a very curious way. If you look at the surface of the sponge through a magnifying-glass, you will see that it is pierced by a great many very tiny holes as well as by a number of bigger ones. Now water is always passing in through the small holes and out again through the big ones; and as it does so the little creatures manage to suck out all the tiny atoms of animal and vegetable matter which were floating about in it. PLATE XLIV THE GRANTIA SPONGE (3) This is quite a small sponge, which you may often find by hunting about in the rock-pools just above low-water mark. Sometimes it clings to sea-weeds, and sometimes it hangs down from the surfaces of the rocks; and when you find one you are almost sure to find several others close by. In appearance, they are rather like little flat white bags, or purses; and when they reach their full size they are generally about an inch long and an inch and a half wide. PLATE XLIV FORAMINIFERA (4) “Foraminifera!” That is rather a long name; isn’t it? But if we cut it in two, and strike out one of the letters, we shall see what it means. _Foramin-(i)-fera_. Now the first part of the name is a Latin word which means “a hole,” and the last part is another Latin word which signifies “bearers.” So “foraminifera” means “hole-bearers,” and this title has been given to certain very tiny creatures which live in the sea because they inhabit shells, which are pierced all over by numbers and numbers of still tinier holes.