Schenck mentions a calculus perforating the bladder and lodging in the groin.

Simmons reports a case in which a calculus passed through a fistulous sore in the loins without any concomitant passage of urine through the same passage.
Vosberg mentions a calculus in a patent urachus; and calculi have occasionally been known to pass from the umbilicus.

Gourges mentions the spontaneous excretion of a five-ounce calculus; and Thompson speaks of the discharge of two calculi of enormous size.
Of the extravesical calculi some are true calculi, while others are simply the result of calcareous or osseous degeneration.

Renal and biliary calculi are too common to need mention here.

There are some extraordinary calculi taken from a patient at St.