KEY TO THE MODEL OF A POTATO PLANT 



SECTION I. GENERAL VIEW 

 Number references as for Section V below 



SECTION II. EPIDERMIS OF THE PLANT 



1. Flower. 



2. Fruit. 



3. Diseased Leaf. 



4. Healthy Leaf. 



(a) Midrib. 



(6) Vein. 



5. Stem. 



6. Healthy Tuber. 



7. Diseased Tuber. 



8. 9, Roots. 



SECTION III. ASSIMILATION 



Number references as for Section II above 



(a) Denotes Inorganic Materials. (b) Denotes Organic Materials. 



SECTION IV. THE FLOW OF SAP 



Number references as for Section II above 



(a) Denotes Inorganic Sap. (b} Denotes Organic Sap. 



SECTION V 



1. Flower (reduced). 



2. Flower (natural size). 



3. Calyx. 



4. Corolla. 



5. Stamens. 



6. Style with Stigma. 



7. Ovary. 



8. Pollen Passage. 



9. Petals. 



10. Fruit (reduced). 



1 1. Fruit (natural size). 



12. Seeds. 



13. Stem. 



14. Roots. 



15. Healthy Leaf (Upper Surface). 



16. Epidermis of Leaf. 



17. Palisade Cells with Chlorophyll 



Granules (very highly magnified). 



1 8. Leaf Vein with Sieve Tubes (very 



highly magnified). 

 19 Spongy Parenchyma (very highly 



magnified). 

 20. Stomata. 



21. Diseased Leaf (Upper Surface). 



22. Epidermis destroyed by Fungi (very 



highly magnified). 



23. 24, Palisade Cells and Spongy Paren- 



chyma destroyed by Fungi (very 

 highly magnified). 



25. Stomata. 



26. The Potato Disease (Section of the 



Leaf). 



27. Healthy Tuber. 



28. Eyes. 



29. Skin. 



30. Starch Grains coloured blue by Iodine 



(very highly magnified). 



31. Section with Cellulose Threads. 



32. Back View of Healthy Tuber. 



33. Diseased Tuber with Fungus Growths. 



34. Destruction of Skin by Fungi. 



35. Destruction of Starch Grains by Fungi. 



36. Destruction of Cellulose Threads by 



Fungi. 



37. Back View of Diseased Tuber. 



