as a favor to a friend who is travelling to a national meeting, i agreed to cover her morning classes Th., Fri., and Mon. now, i'm such a good person that i agreed to do this tho' this will mean i will be more sleep-deprived than is usual. Joan gave me carte blanche so Thursday's group got a dose of chemistry and math which freshmen biology students seem to think have no place in biology. Fri. i'm unsure how i got on a particular tangent but i introduced 'the chirrens' to Cymothoa exigua, or The Tongue Louse. this critter is an isopod which crawls through a host-fish's gills.....mates with any appropriate and available partner on the gill plates....then the female travels into the mouth, eats the tongue, and latches on to the stump of the tongue and begins to function as the fish's tongue. it's the only example known of a parasite functionally replacing an organ. yeah, the students all kind of got the creeps.