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...