The blood basophils lead a shadowy existence in the field of hematology, even now, 100 years after their discovery by PAUL EHRLICH. In clinical medicine they were hardly noticed for many decades, since they occur in such small numbers in the blood that small and moderate variations in the basophil count were not detectable with common count ing methods. This situation has changed since the in troduction of direct counting methods. It was noticed, for example, that the blood basophil count is increased in hy perlipemia. In the field of pathology the blood basophil was prac tically overlooked until recently. This was due to the fact that with common fixations in aqueous solutions the granules dissolve, so that the cells can no longer be stained specifically and therefore escape observation. This problem was solved through special fixing solu tions. However, interest in the blood basophils remain ed confined to only a few research groups.

A. Basophils of the Peripheral Blood

I. Basophil Count
II. Light-Microscopic Morphology
III. Phase-Contrast Microscopic Morphology
IV. Electron-Optical Morphology
V. Cytochemistry of Blood Basophils
VI. Comparative Studies on the Morphology of Blood Basophils
B. The Origin of Blood Basophils
I. Literature Review
II. Detection of Blood Basophils and Their Precursors in Normal Human Bone Marrow
III. Evidence of Basophil Descent from Promyelocytes
C. Biochemistry and Function of Blood Basophils
I. Heparin in Blood Basophils
II. Histamine in Blood Basophils
III. Granulolysis and Kinetic Properties of Blood Basophils
D. The So-Called Basophilic Leukemias
I. Review of the Literature
II. Clinical and Pathoanatomical Features
III. Cytomorphology and Cytogenesis of Leukemic Blood Basophils
IV. Nosology of the So-Called Basophilic Leukemia.