2. =In pemphigus.= Neusser first recorded that an extraordinarily great, indeed a specific eosinophilia was found in many cases of pemphigus. This interesting observation has been confirmed on many sides, in particular by Zappert, who once observed 4800 oxyphil per mm.^{3} 3. In acute and chronic =skin-diseases=. Canon was the first to notice that in a fairly large number of skin-diseases, especially in prurigo and psoriasis, the eosinophil cells are increased up to 17%. The observation of Canon is worthy of attention, that the increase of the eosinophils is connected with the degree of extension of the disease, rather than with its nature or local intensity. In a case of acute widely distributed urticaria, A. Lazarus found the eosinophils increased to 60% of the leucocytes, a number which after the course of a few days again sank to normal. 4. =In helminthiasis.= The first observations on the occurrence of eosinophilia in helminthiasis we owe to Mueller and Rieder, who obtained fairly high values (8.2 and 9.7%) in two men suffering from Ankylostomum duodenale. Shortly afterwards Zappert stated that he had found a considerable increase of the eosinophil cells in the blood, reaching 17% in two cases of the same disease; at the same time he demonstrated Charcot's crystals in the faeces. In a third case of Ankylostomiasis Zappert found no increase of eosinophil cells in the blood, nor the crystals in the faeces. Almost simultaneously, Siege made similar observations. For a detailed working out of this important branch we are greatly indebted to Leichtenstern. Under his direction Buecklers established the interesting fact that Ankylostomiasis in its relation to eosinophilia does not occupy a special place in diseases caused by worms. All kinds of Helminthides, from the harmless Oxyuris to the pernicious Ankylostoma, may bring about an increase of the eosinophil cells in the blood, often to an enormous extent[28]. Buecklers reports an observation of 16% eosinophils in Oxyurides, of 19% in Ascarides; and Prof. Leichtenstern, as we learn from a private communication, has quite recently found 72% eosinophil cells in a case of Ankylostomiasis, and 34% in a case of Taenia mediocanellata. It is well worthy of note that Leichtenstern was able to observe numerous eosinophil cells in the blood in those cases where Charcot's crystals were abundantly contained in the faeces. Since eosinophil cells and Charcot's crystals have elsewhere been observed to be interconnected phenomena (for example in bronchial asthma, in nasal polypi, in myelaemic blood and bone-marrow) one must fall in with Leichtenstern's supposition that eosinophil cells ought also to be found in the intestinal mucus in cases of Ankylostomiasis. Positive observations on this point as yet are wanting.