part u.] THE INSECTS WHICH VISIT FLOWERS. 57 
the maxillary palps elongate also, in order to act still as organs 
of touch. But the maxillary palps are soon outstripped by the 
lamin, the labial palps, and the tongue, and becoming useless 
gradually abort; the laminz and labial palps continue to advance 
to the full extent of elongation of the tongue. This difference is 
explained by the rise of a new function which the labial palps and 
lamine assume, and which renders them quite indispensable and 
renders the maxillary palps quite unnecessary. For as the tongue 
elongates, the laminz develop more and more into a sheath closely 
surrounding the tongue, which not only protects it in retraction 
and when being thrust into a tubular flower, but also comes to 
Fic, 17.—Tip of Hive-bee’s tongue. Highly magnified. 
1.—End of tongue, seen from above. The covering bearing the whorls of hairs (Q) is torn away 
at G to expose the capillary tube, 
2.—The capillary tube with the covering removed, and opening into the spoon-shaped hollow. 
Seen from below 
3.—Side view of the same. 
C, capillary tube; W, its wall; H, skin adhering to the capillary tube; G, ring, formed by 
the expanded bases of the hairs ; Q, whorls of hairs; LZ, spoon-shaped hollow. 
In 1 the hairy, concave upper side is seen ; in 2 the lower, convex, nearly naked side. 
play the part of a suction-tube, in which the tongue, perhaps by a 
progressive erection from before backwards of the whorls of hairs, 
conveys the honey taken up at its point back towards the mouth. 
In this the labial palps are also concerned, for their two or three 
proximal joints become flattened and help the laminz in closely 
surrounding the tongue, while the last joint or the two last retain 
their original function as organs of touch. As soon as the proximal 
joints of the labial palps have come in this manner to form part 
of the suctorial apparatus, they naturally elongate pari passw with 
the tongue and the lamine, and get transformed into long, thin, 
