Photomicrograph of a semithin section of a termite's gut stained with haematoxylin and eosin. The gut appears to be packed with Trichonympha - a genus of protists found in the gut of many termite species. These symbiotic flagellates aid the termite in the digestion of cellulose in its food.
B0007739 Trichonympha in a section of termite gut. Wellcome Images available under the following creative commons usage http://creativecommons.org/licenses/by-nc-nd/2.0/uk/