This beautiful collection of microscope slides of insect tongues is up for auction on eBay right now. The hammer goes down on Saturday and the current bid is $40. From the listing:
A selected group of professional mounts of insect tongues. These have been chosen to show a variety of feeding methods. Included are an opaque mount of a Hummingbird Hawk Moth tongue, those of Bee, Butterfly, Fly and the proboscis of a Blowfly. The most delicate is that of the Cricket, which has been beautifully arranged. Microscopic examination shows many interesting details.
Link (Thanks, Michael-Anne Rauback!)