Field Notes Journal a personal natural history of place

IV.3 Observation of Diatoms

Aim

To study the form and structure of diatom frustules.

Specimen & Apparatus

• Pond water or scrapings from wet stone
• Pipette or needle
• Slide and coverslip
• Water
• Compound microscope

Method

1. Place a drop of the sample on a slide.
2. Apply a coverslip carefully.
3. Examine under low power to locate diatoms.
4. Increase magnification to observe detail.
5. Adjust illumination to enhance contrast.

Observations to Make

• Shape and symmetry of diatoms.
• Presence of fine surface markings.
• Variation in form between individuals.
• Clarity of detail under different illumination.