Before concluding my summary notice of the human hydatids contained in the metropolitan and certain other museums, there is an interesting literary contribution that I cannot pass unnoticed. In the November number of the ‘Indian Medical Gazette’ for 1870 an article occurs in which it is stated that the Calcutta Medical College Museum contains eighteen specimens of hydatid cysts of liver. This fact was, it seems, originally adduced to show, not the frequency, but rather the rarity, of the occurrence of hydatids in India. However, from a valuable communication by Dr James Cleghorn, which was published in the same periodical for the following March, it appears that hydatids of the liver are much more common in India than is generally supposed. This, he says, is owing to the circumstance that many of the so-called cases of tropical abscess are neither more nor less than examples of hydatid cysts that have suppurated. Besides Cleghorn’s evidence, we have the previous testimony of the Inspector General I. M. D., whose Report for 1868-69 I have already referred to in connection with _Cysticercus_ in beef. He says: “During some three months’ regular observation of the animals killed at the Commissariat slaughter-house here, at least 70 per cent. of the beef livers may be calculated as thus affected. Cobbold, writing of the _Tænia echinococcus_, says that ‘this little tapeworm infests only the dog and the wolf.’ Therefore, considering the immense number of pariah dogs fed on the refuse of animals infected with hydatids, it seems more than probable that the parasite must attain its strobila condition in their intestines, and through them be eventually disseminated over the pastures on which the cattle graze.” I now turn to a neglected phase of the subject from which much practical instruction may be gathered. The consideration of the pathological phenomena of hydatid disease as it affects the lower animals is of high interest, and no prejudice should induce any medical man from accepting such useful data as may be gathered from this source. The facts of hydatid parasitism in animals, though often peculiar, are, for the most part, of an order similar to those presented in the human subject. If any medical practitioner thinks it beneath his dignity to study the pathology of the lower animals, the conduct of John Hunter in this respect is a standing protest against such narrowness.