lOO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



do SO even when the sting is detached from the body of the bee. At 

 the same time the contents of the poison sack are poured into the bulb 

 of the sting and driven through the poison canal by the action of the 

 valves on the bases of the lancets. The poison escapes through a 

 ventral cleft near the tips of the lancets. 



VIII. ANNOTATED LIST OF MUSCLES 



The terms origin and insertion are conventional in descriptive 

 myology for denoting muscle attachments respectively at the fixed 

 and the movable ends of the muscle. Literally there is no "insertion" 

 of insect muscles, the muscle fibers being attached directly on the 

 integument by means of cuticular tonofibrillae. Insect tendons, more- 

 over, are merely slender apodemal ingrowths of the integument. The 

 incongruous expression "inserted on" has thus become current in 

 entomological writing, referring in some cases to the muscle attach- 

 ment proper by tonofibrillae, in others to the attachment of the 

 apodemal tendon on the integument. 



In the following list of the bee's muscles reference is made prin- 

 cipally to the work of Morison (1927) on the muscles of the honey 

 bee, and to that of Duncan (1939) on the wasp. Citations of the more 

 fragmentary work of earlier writers are given by Morison, in part by 

 the writer (1933, 1941), and need not be repeated. In general there 

 will be no difficulty in identifying the muscles listed here with those de- 

 scribed by Morison, notwithstanding differences in functional names ; 

 a few discrepancies are noted. 



/. Adductor of the lahriiin. — A slender muscle arising on the frontal 

 region between bases of antennae, inserted by a long tendon laterally 

 on posterior margin of base of labrum. {Levator labri Morison.) 



2, J, 4, 5, Extrinsic muscles of the antenna (fig. 2 A, C). — Four 

 muscles arising on anterior arm of tentorium, inserted on base of 

 antenna, 



6. Levator of the antennal Hagellunt (fig. 2 H). — A slender muscle 

 arising on dorsal wall of scape, inserted dorsally on base of pedicel. 



y. Depressor of the antennol flagclhim (fig. 2H). — Origin on 

 ventral wall of scape, insertion ventrally on base of pedicel. 



8. Abductor of the mandible (fig. 3 I). — A flat muscle arising by 

 spreading fibers on genal and postgenal walls of cranium behind 

 lower part of compound eye, inserted by strong apodeme in membrane 

 between mandibular base and pleurostomal margin of cranium (fig. 

 Z^,SAp). 



