To summarize, we have been able to demonstrate:
(1) In a case of acute trichinosis an extensive leucocytosis, with great absolute and relative increase in the number of eosinophilic cells in the blood, associated with a coincident decrease in the quantity of neutrophilic elements.
(2) From the examination of specimens of muscle removed during life, besides the peculiar degenerations of the muscle, a longitudinal splitting of some of the fibres; a remarkable transverse splitting of others; a great proliferation of nuclei, about many of which vacuoles are seen; and large numbers of polymorphonuclear eosinophilic cells, which are especially prevalent in the more degenerated areas.
(3) In a second case (after death), besides similar changes in the muscle, large numbers of eosinophiles throughout the infested portion.
(4) In two other cases, during life, a great increase of the eosinophilic cells in the blood, with a coincident decrease of the polymorphonuclear neutrophiles, associated with leucocytosis, though of less extent than in the first case.
(5) In pieces of muscle removed in these last two cases changes in most respects similar to those cited in the first case, but of less degree.
(6) The similar character of the nuclei of the eosinophiles and the neutrophiles both in the blood and in the muscle, and the presence in the first case of certain cells which might be regarded as forms transitional between neutrophiles and eosinophiles, suggesting the possibility that the increase in the latter elements may, in these instances, take place in the muscles by direct transition from the neutrophiles.