The Life Processes of the Individual 139 



is pulled and pushed through the maxillae. This motion 



doubtless effects a pumping action, bringing the liquid 



through the temporary tube Ant 



formed by the .curling of the 



glossa. It is probably sucked 



farther by the pharynx. The 



glossa is also retracted into 



the mentum and this with its 



own contractility gives it great 



flexibility of movement. 



Thorax. 



As explained earlier (p. 99), 

 the functional thorax of the 

 bee (Figs. 73 and 74) con- 

 sists of the three segments 

 which form the thorax in 

 other orders of insects and 

 the segment which is the first 

 abdominal segment of other 

 orders. This modification is 

 found in most other Hymen- 

 optera 1 but the fact has seem- 

 ingly escaped most writers on 

 bees. The prothorax (1st 

 thoracic segment) is reduced 

 and the first pair of legs, 

 arising from this segment, are 

 loosely attached. The meso- 

 thorax (2d thoracic segment) 

 is specially well developed to 

 accommodate the large mus- 

 cles which propel the fore wings, while the metathorax (3d 

 thoracic segment) is reduced, consisting only of a narrow 

 plate (T8), the metatergum,. and two lateral plates on 



Mb 



VT 



'Mb 



VLT 



,-VlT 



FIG. 73. Dorsal view of ventral 

 walls and internal skeleton of 

 worker. Much enlarged. 



595. 



Snodgrass, R. E., 1909. Proc. U. S. Nat. Mus., XXXVI, pp. 511- 



