On the 25th of November, 1852, a fine female Zebra, whilst at play within its paddock, accidentally broke its neck. The animal had always appeared to be quite healthy, and it was in perfectly good condition—but, upon examination, its liver was found to be one mass of cysts, varying in size from a child's head downwards. The liver was taken out of the body on the day succeeding the animal's death—and on the 27th I proceeded to examine the contents of one of the largest cysts (with a portion of its wall) and one of the smaller cysts. It was at once obvious that the cysts contained the Echinococcus veterinorum , and I may here mention that the Echinococci were in full life, and remained so for three days, until, in fact, the fluid in which they were contained had become slightly offensive. It will conduce to clearness, perhaps, if I