Plate 69. — Seed Structure. 



A. Transverse Section, Black Mustard Seed. 1. Epidermal layer of testa. 

 2. Subepidermal layer of teBta. 3. Palisade layer of testa. 4. Pigment layer or 

 tegmen. 5. Endosperm. 6. Parenchyma of cotyledon containing aleurone. 



B. Powdered Black Mustard Seed. 1. Epidermal cells. 2. Subepidermal and 

 Palisade layers consolidated. 3. Palisade cells. 4. Parenchyma of cotyledon. 

 5. Aleurone grains. 6. Mucilage cells. 



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