cross-section of egg sac of a common house spider (parasteatoda tepidariorum) - 19th century - 液囊 幅插畫檔、美工圖案、卡通及圖標
digital illustration spina bifida, meningocele, where protective covering around spinal cord protrudes through malformed vertebra to form sac filled with cerebrospinal fluid - 液囊 幅插畫檔、美工圖案、卡通及圖標
illustration of dinosaur foetus in egg showing yoke sac and amniotic membrane - 液囊 幅插畫檔、美工圖案、卡通及圖標動物的蛋