The Worm in the Grasshopper

The grasshoppers in the meadows below the city of Philadelphia are very much infested with a species of Gordius, probably the same as the former, but in a different stage of development. More than half the grasshoppers in the locality mentioned contain them; but those in drier places, as in the fields west and north of Philadelphia, are quite rarely infested, for I have frequently opened large numbers without finding one worm. The number of Gordii in each insect varies from one to five, their length from three inches to a foot; they occupy a position in the visceral cavity, where they lie coiled among the viscera, and often extend from the end of the abdomen forward through the thorax even into the head; their bulk and weight are frequently greater than all the soft parts, including the muscles, of their living habitation. Nevertheless, with this relatively immense mass of parasites, the insects jump about almost as freely as those not infested.

Joseph Leidy, Philadelphia's great microscopist, opened grasshoppers from the meadows below the city and found worms up to a foot long coiled inside insects that went on jumping almost as freely as the rest.

Source: Joseph Leidy, A Flora and Fauna within Living Animals, Smithsonian Contributions to Knowledge (Washington: Smithsonian Institution, 1853), Introduction, p. 6 (footnote). Text: Internet Archive scan. Public domain in the US. Text note: Copied from the scan's OCR and checked word for word against the page image. One OCR error was corrected ("Grordit" to Gordii). Pairs with: Cups: Four or Eight of Cups, or Major Arcana: The Hanged Man A note from 2026: Hair-worms are their own phylum, not true nematodes. Leidy did not know the life cycle. We now know the worm drives its host toward water, and the adult escapes into it.

Public domain in the United States.