FIG. 86.—Tongue or ligula of the honey bee: _A_, under side of the tongue; _lp_, labial palpi; _r_, _r_, rod; _p_, pouch; _sh_, sheath; _gh_, gathering hairs; _b_, bouton or spoon. _B_, under lip or labium, with appendages, partly dissected; _l_, lora or submentum; _a_, _a_, retractor linguæ longus; _sd_, salivary duct; _rb_ and _b_, retractor linguæ biceps; _mx_, maxillæ; _lp_, labial palpi; _pa_, paraglossa; _gr_, feeding groove; _sh_, sheath of ligula. _C_, _D_, _E_, sections of ligula; _hp_, hyaline plate of maxilla; _h_, hairs acting as stops; _mx_, maxilla; _lp_, labial palpi; _sd_, side duct. _F_, cross-section of extremity of tongue near the “spoon”; _th_, tactile hairs; _r_, rod; _n_, nucleus; _gh_, gathering hairs. _G_, cross-section of tongue without gathering hairs, × 400 times; _sh_, sheath; _b_, blood space; _t_, trachea: _ng_, gustatory nerve; _cd_, central duct; _sd_, lateral duct; _pm_, plaited membrane. _H_, same as _G_, but magnified two hundred times, and with _pm_, plaited membrane, turned outwards; _h_, closing hairs; _lp_, labial palpi; _b_, blood; _n_, nucleus; _r_, rod; _h_, closing hairs. _I_, small portion of the sheath; lettering as before. _K_, extremity of the tongue, with spoon; _b_, branching hairs for gathering.—After Cheshire. ] Cheshire then settles the question which has been in dispute since the time of Swammerdam, whether the bee’s tongue is solid or tubular. He agrees with Wolff that the duct is a trough and not a tube, and proves it by a satisfactory experiment. He remarks: [Illustration: FIG. 87.—Longitudinal section through the head of the honey bee, ♀, just outside of right antenna: _ant_, antenna with three muscles attached to _mes_, mesocephalic pillar; _cl_, clypeus; _lbr_, labrum; 1, chyle-gland (system no. 1, of Siebold); _o_, opening of the same; _oc_, ocellus; _br_, brain; _n_, neck; _th_, thorax; _oe_, œsophagus; _s.d_^2, _s.d_^3, common salivary ducts of systems 2 and 3; _v_, salivary valve; _c_, cardo; _ph_, pharynx; _mx′_, labium; _mx.′p_, labial palpi; _mt_, mentum; _mx_, maxilla; _hyp_, hypopharynx; _s_, bouton.—After Cheshire. ]