80 
STING STRUCTURE. 
continue for a considerable distance, winding amongst 
the malpighian tubes and outside the chyle stomach 
like two white tubular threads which have their ex- 
tremities enlarged. These enlargements contain the 
secreting glands. They produce the formic acid of 
which the poison consists, and Girard (48) says it is 
possibly associated v/ith some other toxic agents. For 
this reason ammonia is recommended as a curative 
agent, as it neutralises the formic acid. Although this 
acid acts as a poison if one bee stings another, Dennler 
has shown that a certain quantity can be taken into 
the bee’s stomach, as he found, if mixed with food in 
his remedy for foul brood, it has no ill effects. 
Girard (48) says that the poison is driven from 
the sac by the muscles which project the sting, and at 
the same time press on the poison sac, ex])elling the 
venom. Carlet (20) has more recently found that 
the poison sac has not a muscular investment, that it 
is not contractile, and cannot in any way act on the 
contents, which are therefore pumped out in the 
manner we have already described. 
Attached to the stinging apparatus are two palpi, 
or feelers (Fig. 34, e e). That they serve this purpose 
is evident, because they are provided with delicate 
feeling hairs, and are always protruded in advance of 
a thrust made by the sting, to ascertain the most 
vulnerable point of attack. The poison of a bee 
on drying cracks, and appears like Fig. 36, while in 
it will be found numbers of oil globules. Leuckart 
found this oil was secreted by a special gland (frontis- 
piece, ii\ and both he and Vogel (166) state that 
