In this way other clinical observations may be explained. Gollasch has found that the sputum of asthmatic patients contains, in addition to Charcot-Leyden's crystals, eosinophil cells only. One must therefore assume that within the bronchial tree there exists material which attracts the eosinophils. This supposition is also supported by the close connection that obtains, according to many observations, between the severity of the disease and the eosinophilia. Thus v. Noorden records that the eosinophil cells are more numerous about the time of an attack. They accumulated in especially large numbers after attacks had rapidly occurred several days in succession. =That the increase of the eosinophil cells in this instance is directly connected with the attacks, and is not the expression of a permanent constitutional anomaly=, is shewn by a case in which v. Noorden found 25% eosinophils during the attack, and a few days later could only observe one example in twelve cover-slip preparations: a diminution therefore of this group of cells. The observations of Canon in skin-diseases are quite similar, for he shewed that the extension of the disease determines the degree of eosinophilia more than its intensity. And it is the former factor which directly determines the quantities of the specific agent that pass into the blood. To the Mueller-Rieder hypothesis, and the chemiotactic theory of eosinophil leucocytosis a third has lately been added, which may be shortly called =the hypothesis of the local origin= of the eosinophil cells. A. Schmidt has, with special reference to asthma, raised the question "whether in the extensive production of eosinophil cells in asthma, local production in the air passages is not more probable than origin from the blood. One may well regard the increase of the eosinophil cells in the blood of an asthmatic as secondary." This view, which has also been advocated by other authors, rests more particularly on the following facts and considerations: 1. That in various diseases of the nose, especially in mucous polypi and hyperplasia of the mucous membrane (Leyden, Benno Lewy and others), a great accumulation of eosinophil cells is found in these tissues, whilst they are apparently not increased in the blood. This objection is easily laid aside from the chemiotactic point of view. For if in the places in question substances are present which act chemiotactically on the eosinophil leucocytes, in the course of time marked accumulation must occur, without an increase of their number in the blood. One might as well conclude from Neumann's experiment in lymphatic leukaemia, for example, where the artificial suppuration consisted only of polynuclear neutrophil cells, that the polynuclear cells were formed in the tissue, since in the blood they were present in very small percentage. For in this case too the same incongruity between the blood and the particular tissue exists.