old engraved illustration of shows the appearance under the microscope of a hair, the cells overlapping one another like tiles on a roof - 毛幹 個照片及圖片檔
old engraved illustration of shows the appearance under the microscope of a hair, the cells overlapping one another like tiles on a roof - 毛幹 個照片及圖片檔式樣, 背景 - 主題
old engraved illustration of longitudinal section through the middle toe of human embryo, human body tissue - 毛幹 個照片及圖片檔細胞, 基本組織, 顯微鏡
