. The bee-keeper's guide : or Manual of the apiary . Bee culture; Bees. Drone Peculiarities, lOI Landois showed many years since, that the hum of bees and other insects, was due first to vibrations of wings, sec- ondly to vibrations of the abdominal rings and,thirdly, to what he styled true voice in the thoracic spiracles, where there are cavities which he thought were voice cavities. He thought the humming tone of bees and other insects, came from the spiracles. The drone's flight is more heavy and lumbering than that of the workers. Their ligula ( Fig. 8),labial palpi and maxillae—like thesame in thequeen bee— Fig. 29. Fig. 30.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Cook, Albert John, 1842-1916. Chicago, Ill. : George W. York & Co.