i BEES PROBOSCIS I 5 



pharynx ; one pair of these strap-like pieces extends backwards 

 from the two sides of the base of the epipharynx ; Huxley called 

 them sclerites of the oesophagus ; a better name would be 

 epipharyngeal sclerites (Fig. 7, a) : the other pair pass from the 

 terminations of the epipharyngeal sclerites, along the front face of 

 the hypopharynx, down to the mentum, their lower parts being 

 concealed by the stipites of the maxillae ; these are the hypo- 

 pharyngeal sclerites, and we believe it will prove that they play 

 a highly important part in deglutition. When the labrum of a 

 bee is raised and the proboscis depressed, the epipharynx is seen 

 hanging like a curtain from the roof of the head ; this structure 

 plays an important part in the act of deglutition. The entrance 

 to the pharynx, or commencement of the alimentary canal, is 

 placed below the base of the epipharynx. As we are not aware 

 of any good delineations of the basal parts of the proboscis we 

 give a figure thereof (Fig. 7). The maxillae in the higher bees 

 are extremely modified so as to form a sheath, and their palpi 

 are minute ; in the lower bees the palpi have the structure usual 

 in mandibulate Insects. 



Returning to the consideration of the lower lip, we find that 

 there is attached to the mentum a pair of elongate organs that 

 extend forwards and form a tube or sheath, enclosed by the 

 maxillary sheath we have previously mentioned ; these are the 

 greatly modified labial palpi, their distal parts still retaining the 

 palpar form ; and in the lower bees the labial palpi are, like the 

 maxillary, of the form usual in mandibulate Insects. Between 

 the labial palps and the central organ of the lip there is attached 

 a pair of delicate organs, the paraglossae. 



There remains for consideration the most remarkable part of 

 the proboscis, the long, delicate, hairy organ which the bee 

 thrusts out from the tip of the shining tube formed by the labial 

 palps and the maxillae, described above, and which looks like 

 a prolongation of the mentum. This organ is variously called 

 ligula, lingua, or tongue. 1 We prefer the first of these names. 



According to Breithaupt and Cheshire the structure of the 

 ligula is highly remarkable ; it is a tube (filled with fluid from 

 the body cavity), and with a groove underneath caused by a large 

 part of the circumference of the tube being invaginated ; the 



1 Leuckart proposed the terra lingula ; but the word gives rise to the impression that 

 it is a mistake for either lingua or ligula. Packard calls the part " hypopharyux. " 



