Page:Insects - Their Ways and Means of Living.djvu/246

 upon the finer structure and the mechanism of the parts before us.

Each one of the second pair of bristles has a furrow along the entire length of its inner surface, and the two



bristles, small as they are, are fastened together by interlocking ridges and grooves, so that their apposed furrows are converted into a single tubular channel. In the natural position, these second bristles lie in the sheath of the beak (Fig. 121 A) between the somewhat larger first bristles. Their bases separate at the tip of