156 INTRODUCTION 
hair, which may even spoil the flavour of the nectar next tasted. But by examining 
the ligula of a highly specialized bee under a high power of the microscope, a special 
arrangement by which this imperfection is obviated will easily be recognized. In less 
specialized bees the whole length of the tongue is supported by a massive chitinous 
rod; but in more specialized bees this rod is converted into a capillary tube, which 
opens into the hollow of the spoon-shaped lappet at the tip of the ligula. As soon as 
this ‘spoon’ is immersed in nectar, part of it rises in the capillary tube to the base 
of the ligula and to the taste-organs. Should the nectar, when tasted, prove 
disagreeable to the bee, it need not even begin to suck, and can easily expel the 
minute quantity of liquid that fills the tube.’ (Cf. O. J. B. Wolf, ‘Das Riechorgan 
der Biene,’ 1874.) 
Fig. 67 represents the head of a humble-bee in the suctorial position, with 
the proboscis half extended. If now, from this position, the base of the ligula is 
y74- 
10 RT 
Fic. 67. Head of Bombus hortorum, L. 9, with proboscis half extended; seen from the side 
(after Herm. Miiller). (x 7.) References as in Fig. 66. 
retracted into the hollow end of the mentum (as shown in Fig. 68), its end (ww) 
is drawn back saturated with nectar into the suctorial tube. If the cardines 
(Fig. 67, c), now turned vertically downwards, are rotated backwards, the base of 
the suctorial tube (at pm) will be drawn back to the opening of the mouth (between 
the labrum and the bases of the mandibles, and by a simultaneous sucking action 
of the sides of the body, and pressure of the erectile whorls of hair, the nectar is 
quickly carried from the tip of the ligula into the mouth’. 
1 Hermann Miiller thinks he can conclude with certainty that the whorls of hair have the 
function described above from experiments he made on chloroformed bees and humble-bees. In 
these, sometimes, if the tip of the ligula was dipped in syrup before complete loss of consciousness, 
the suctorial movements were induced so slowly that their separate stages could be clearly dis- 
tinguished. They were as described above. What went on between the chitinous plates of the 
laciniae and labial palps was of course invisible, but when these parts were drawn aside, after the tip 
of the ligula had been moistened with syrup, a successive erection of the whorls from the tip to the 
base could sometimes be clearly seen. The fact that the basal part of the ligula, which is retracted 
into the hollow of the mentum, is free from whorls of hair is in accordance with this interpretation. 
[But in the English translation of Miiller’s book (p. 61), which incorporates more recent observations of 
