flower to another, or when travelling back to the hive. Besides the two stomachs, the abdomen contains certain glands to which we shall refer when we come to speak of honey. CHAPTER XVII THE BREATHING APPARATUS Insects do not breathe by means of lungs as we do but through tiny air-holes, called “spiracles.” This name comes from the Latin _spiraculum_, meaning an air-hole, which in turn is derived from _spirare_, to breathe. Crawling insects do not need nearly so much air as flying insects, and so their breathing apparatus is not so large. In the bee the breathing tubes spread over almost the whole body, two of the largest extending along each side of the abdomen. The rings of the abdomen slightly overlap one another, and if you watch a bee carefully you will notice that they are constantly slipping in and out, like the joints of a folding telescope which is being opened and closed. This is really the action of breathing, and the bee draws in and then drives out air. If you have ever rescued a fly which has fallen into the milk, you will remember that it at once commences to clean itself vigorously with its legs. It does not do this to make itself tidy, but to clean out the milk which clogs its air-tubes and is thus choking it. It is interesting to notice that the mouth of each air-tube has a number of tiny hairs; these serve to keep out dust, which would interfere with the breathing. The air-tubes branch off one from another like the roots of a tree, and in order to give you some idea of how very small they are, I may tell you that it has been found that a bundle of a quarter of a million of them would hardly be any bigger than an ordinary human hair! [Illustration: PLATE XIII (_a_) Photo-micrograph by] [E. Hawks Sting of Bee (_b_) Photo-micro. by] [E. H. Sting, showing Barbs] CHAPTER XVIII THE STING We have now only the sting left to consider. I need not tell you what it feels like to be stung, as no doubt a good many of you have had that interesting operation performed upon you by some bee or wasp which you have annoyed! How very frightened every one is of the sting of a bee, and those people who have never been stung are perhaps the most frightened of all. After all, the sting is not so painful, and it is very interesting to watch the angry little worker drive its sharp weapon into our hand; besides which it is actually good for us to be stung, and the reason of this I shall presently tell you. The sting is situated at the very tip of the abdomen. It would take up too much space to fully describe all the details of its construction, and therefore I shall simply tell you about the chief parts, and also how it works.