These Bees are much more abundant than is usually thought. In summer-time it is hardly possible to find a rose-bush on which are not a number of leaves from which pieces of variable size and shape, but always with a curved outline, have been cut as with scissors. While cutting them, the Bee seems to trace out her pattern, as it were, by using her feet like one leg of a pair of compasses, and her head as the other leg. As soon as she has nearly finished the operation, she poises herself on the wing, to prevent her weight from tearing away the leaf irregularly, and then, while still on the wing, makes the last few bites, and severs the leaf entirely. THE CHISEL AND THE ADZE. Already we have seen how exact is the analogy between the scissors and the turtle-jaw. As we are upon the subject of cutting instruments, we will continue it, trying to discover some further analogies. On the right hand of the illustrations we see three cutting tools made by human hands--_i.e._ the Chisel, the Stone Adze of Polynesia, and the Steel Adze of this country. We begin with the Chisel. All those who have even a slight knowledge of anatomy know how curiously exact is the resemblance of the Chisel of civilised life to the front tooth of any Rodent animal. The head of the Beaver is here given as an example, but the tooth of a mouse, rat, or rabbit, which can easily be obtained, is quite as good an example. These teeth are made after a very beautiful fashion. Their outer surface is covered with a plate of very hard enamel, while the rest of the tooth is of bony matter, and comparatively soft. Consequently, when the tooth is used, the enamel plate forms a sharp edge, while the rest of it is worn away, thus keeping the chisel-like end in its proper form. [Illustration: TOOTH AND JAWS OF BEAVER.] [Illustration: CHISEL.] The power of these teeth may be appreciated by any one who has been bitten even by so small a rodent as a mouse, the sharp edges meeting in the flesh, and causing a very painful wound. When the teeth are large, as in the Beaver, and the jaws powerful, their force is something wonderful, tree-trunks of considerable size being cut down quite easily. Perhaps some of my readers may not be aware that the Chisel is constructed on exactly the same principle as the tooth of the Rodent animal. It is not entirely made of steel, as is generally thought. In the first place, a valuable material would be needlessly wasted, and, in the next place, the tool would not keep its edge except with infinite labour in grinding.