Today, Susan Perkins of Parasite of the Day is featuring the heart-shaped parasite Giardia, the cause of the commonly known “Beaver Fever“. This parasite was first discovered in 1681 by Antoni van Leeuwenhoek when he was examining his own stool after suffering a bout of diarrhea.
I have sometimes also seen tiny creatures moving very prettily; some of them a bit bigger, others a bit less, than a blood-globule but all of one and the same make. Their bodies were somewhat longer than broad, and their belly, which was flattish, furnished with sundry little paws, wherewith they made such a stir in the clear medium and among the globules, that you might even fancy you saw a woodlouse running up against a wall; and albeit they made a quick motion with their paws, yet for all that they made but slow progress.”
Just the romantic kind of story you want to hear on Valentine’s Day….
Brian J. Ford, author of many books on the history of microscopy has also done some investigation into Giardia, and it can be found in the pdf. document called, The Discovery of Giardia, from which the above quote was taken.