"It is an instrument, made by fixing glasses in such a way to look through, that small things will seem to be very large. Do you not see how some of these little fellows are rolling themselves over in the inside of the flowers, so that the yellow dust is sticking to them? Now their breasts, and legs, and many other parts of their bodies are covered with very short hairs, which catch the dust. The last joint but one of each leg is made exactly like a brush, the hairs being longer there than on any other part; and with these they brush off the dust, and get it into two little heaps. The bags into which they put it, or rather the baskets, are in the thighs of the last pair of legs. These are hollow, so as to form a three-sided basket. The bottom of it is smooth and shining, and appears like horn, and all around the edges are placed very strong, thick-set hairs, like bristles." "What are these for?" "To keep things from falling out of the basket; and these bristles are so strong that even if they heap up more than the basket will hold, the bristles will keep it from falling. Here is a drawing of these legs. [Illustration: Structure of the legs of the Bee for carrying propolis and pollen, magnified.] Besides carrying this dust, they also carry what is called _propolis_." "What is propolis, Uncle Philip?" "It is a gum which is found upon some trees. This they work up into little balls, and knead it until it is a little dry, so as not to stick. This takes the bee sometimes as much as half an hour. When the balls are ready, she passes them backwards with her feet to the basket, puts them in, and gives them a pat or two to make them lie close; and when she adds more, she pats it still harder, and when the basket is full, away she goes to the hive. But there is another curious instrument about the bee. I mean its sting: this is like the head of a barbed or bearded arrow. There is a sheath for it when the bee does not wish to use it; and here is a picture of it. [Illustration: _a_, The sting of a Bee, magnified to show the barbed darts; _b_, the last ring of the abdomen of a Bee opened, showing the sting in its sheath.] But let us now continue our walk." "Well, Uncle Philip, it is really very pleasant to walk with you: it seems as if you met nothing which could not teach us things worth knowing."