i6 



MOUTH OF HUMBLE-BEE. 



[chap. 



Panurgus (Fig. 17), Halictoides (Fig. 18), and Chelos- 

 toma (Fig. 19), we see various stages in the elon- 

 gation of the lower lip, until at length it reaches 

 the remarkable and extreme form which it now 

 presents in the hive and humble bees (Fig. 20), and 



Fig 20. — Head of Humble-bee {Bombus agrorum), with the mouth-parts extended. 

 fia, paraglo-ssEC ; It, ligula ; pi, labial palpi ; pm, maxillary palpi ; la, lamina of 

 ditto : J'tij menrum ; st, stipes ; vtd, mandibles ; c, cardo ; o, eye. 



which enables them to extract the honey from 

 almost all our wild flowers. No bees, ho^vever, 

 have the proboscis so much elongated as is the 

 case with some butterflies and . moths ; perhaps, 

 as Hermann Miiller has suggested, because the 



