The pathological collection connected with St George’s Hospital displays several good hydatid preparations, the entire series representing at least twenty-two separate cases. Of these, fifteen are referable to the liver, that is, if we include Dr Dickinson’s case, already published, where hydatids were found within the hepatic duct. There are two renal cases; also one from the brain (Dr Dickinson’s case), and another where an hydatid was expectorated. Besides these, there are three other highly characteristic examples of echinococcus disease affecting the region of the neck, breast, and axilla respectively. The museum of the London Hospital Medical School contains a large collection of parasites. Out of fifty-seven preparations of entozoa, I found twenty-two referable to hydatids; and, so far as I could gather, all of them belonged to different cases. Only one case seems to have been published in detail. This, though a very old preparation, is a fine example of an hydatid, nearly three inches in length, occupying one of the cerebral hemispheres (‘Edinb. Med. Journ.,’ vol. xv). There is a second brain case, where the vesicles were of small size, but very numerous. Of the other twenty cases, fourteen belong to the liver, two to the spleen, one to the lung, one to the uterus; one being a very large hydatid of doubtful seat, and another being referable to the lumbar region, where it formed a tumour containing “a large number of small hydatids.” Amongst the more remarkable specimens is that described in the MS. catalogue as “a true hydatid cyst developed in connection with the broad ligament.” This preparation, unique of its kind, shows no trace of the ovary, which, indeed, seems to have disappeared altogether. One of the liver cases should rather be classed as abdominal, since the large cyst is situated between the diaphragm and liver, pressing upon the latter organ below and also upon the lung above, but apparently not involving either of these viscera structurally. Another very striking case is that in which there is an external opening communicating with the cyst in the liver, and an internal opening through the diaphragm communicating with the lungs and bronchial tubes. The patient had actually coughed up liver hydatids by the mouth, and had passed others through the right wall of his abdomen. There is another liver case in which the hydatids, in place of escaping externally, had gained access to the inferior cava; and if I understand the MS. record rightly, in the same patient a second hydatid communicated with the portal vein, and a third with the hepatic vein. Lastly, I must add that there is yet another fine preparation of liver hydatids, occurring in a lad, nineteen years of age. He had, it seems, met with “a slight accident, and died with obscure head symptoms;” but the odd part of the case is that at the post-mortem examination there was positively nothing found that could explain the patient’s death.