ii6 THE HONEY-BEE. 



abdomen. These air-holes are called spiracles, or 

 stigmata, and lead into two minute chambers, one 

 behind the other, the outer being provided with a 

 number of short hairs, to prevent the entry of 

 foreign particles likely to obstruct the important 

 passages. 



From these vestibules the air is conducted by 

 tubes, or trachea, into sacs or bladders communi- 



FiG. 32. — Abdomen of Bee, showing Respiratory Organs. 

 a-, Air-sac. b bh, SpiiacleE., 



eating with each other. The largest pair of these 

 cavities is found in the abdomen, and from these two 

 main trunks lead, one into the thorax, and the 

 other to the termination of the abdomen. From the 

 latter there branch out subsidiary tubes, leading into 

 the minuter chambers, called sacculi, or little sacs. 

 Those going upwards do not subdivide till they 



