TONGUE AND MOUTH PARTS. 97 



as well as a better one. Bees have the power, by 

 driving blood into the tongue, of forcing the rod out 

 from the sheath, and distending the wrinkled mem- 

 brane, so that in section it appears as at H, Plate III., 

 the membrane assuming the form of a pouch, given in 

 full-length at A. It will be seen at once that this 

 disposition of parts abolishes the side ducts, but 

 brings the, central duct to the external surface. The 

 object of this curious capability on the part of the bee 

 is, in my opinion, to permit of cleaning away any 

 pollen grains, or other impediment that may collect in 

 the side ducts. The membrane is greasy in nature, 

 and substances or fluids can be removed from it as 

 easily as water from polished metal. If, now, the side 

 of a needle, previously dipped into clove oil in which 

 rosanilin (magenta) has been dissolved, so as to stain 

 it strongly red, be touched on the centre of the rod, 

 the oil immediately enters, and passes rapidly upwards 

 and downwards, filling the trough. I could not resist 

 laughing, while my pulse certainly went faster, as I 

 realised the absurdly simple means which put that 

 matter within the grasp of the tyro, with his simple 

 lens, which had kept many learned doctors wrangling, 

 notwithstanding all their appliances. It is a pseudo- 

 tube, then, and nothing more. Hairs cover it, and 

 these permit of its being entered by the side. 



The impossibility of cleaning, and so the tre- 

 mendous risk, or, rather, the certainty, of clogging, 

 which a closed tube would involve, does not appear 

 to have disquieted those who have been wrongfully 

 describing the bee's tongue as tubular; but there is 

 yet another consideration, which should show us the 



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