Wasps, Bees, and Ants 
461 
sac (p'S.) flows from this into lesser reservoirs in the expanded base of the 
sheath and escapes through the valve (v) along the darts 
into the wound. The tactile (and perhaps olfactory) palpi 
(p) are used to explore the surface of the object to be 
stung. The modifications of the various appendage-like 
parts which compose the sting to form an egg-depositing 
organ (ovipositor) are extremely various and are described 
later in connection with various special groups. The 
number of separate parts or processes which compose 
the ovipositor or sting and which arise from the two ab¬ 
dominal segments next in front of the terminal one is 
six, and some entomologists consider these parts to be true 
appendages, homologous with the legs and mouth-parts. 
In the development of all Hymenoptera the meta¬ 
morphosis is complete, and the larvae are, more than 
in any other order, helpless and dependent for their 
food and safety on the provision or care of the parents 
Fig. 648.—Frontal as¬ 
pect of head of larva 
of mud-wasp. md. y 
mandible; mx., max¬ 
illa; mx.l., maxillary 
lobe; li., labium; 
li.p. } labial palpus. 
With 
many 
Fig. 649. Fig. 650. 
Fig. 649.—Lateral aspect of head of full-grown larva of mud-wasp cleared so as to 
show forming adult head within, i.h., head of adult; i.e., compound eye of adult;, 
l.c., body-wall of larval head; i.ant., antennae of adult; l.md ., mandible of larva; 
i.md., mandible of adult; l.mx., maxilla of larva; i.mx., maxilla of adult; i.mx.p. v 
maxillary palpus of adult; l.li., labium of larva; i.li., labium of adult; li.lip ., labial- 
palpus of adult. 
Fig. 650. Sting of the worker honey-bee. p.gl., poison-gland; p.s., poison-sac; d., dart; 
levers; v., valve; s., sheath; p., palpus. 
species, as the solitary wasps and bees, food is stored up in the cell in which 
