在顯微鏡下的青苔。
馬氏發現到青苔是在自然環境中最親近水管的植物。因此，她試用微觀方法觀察依附水管上青苔的生長形態，並記錄下來。

Moss under a microscope.
MA learnt that moss is a plant is close to water pipes in nature. This piece is a record of MA's observation of a single piece of moss she sampled growing on the water pipe under a microscope.