Photomicrographs of peripheral blood leukocytes displaying the classical staining and morphology of basophils. (A) A basophil from a Wright-Leishman–stained mouse (strain unknown) peripheral blood film. (B) Wright-Giemsa–stained basophil from a peripheral blood film of a mouse on a C57BL/6J background¹⁴  (Fig S2C) (originally published as Supporting On-line Material in Science, 2004;305:1773-1776). (C) The single previous photomicrograph of a mouse basophil appearing in a study by Urbina et al.^{7(Fig 1)} (Reprinted with permission from S. Karger AG, Basel.) (D) A human basophil from a Wright-Giemsa–stained peripheral blood film. Scale bar = 10 μm. The photographs were collected using a Zeiss Axiophot microscope (Carl Zeiss, Thornwood, NY) (Plan-NeoFluar 63×/1.25 mm) and a AxioCam MRc5 digital camera (Carl Zeiss). Adobe Photoshop (San Diego, CA) was used to assemble the figure; however, no enhancements or manipulations of the images were made.