DESCRIPTION OF PLATE I 



Fig. I. — Types of Pollen Grains. — i. Saffron flower. 2. Flax. 3. Pink. 4. 

 Pumpkin and squash. 5. Cloves. Mature pollen grain. 6. Cloves. Immature 

 pollen grain. 7. Onagraceee. Circea lutitiana (Enchanter's Nightshade). 8. 

 Scutellaria. 9. Mallow. Distended by moisture. 10. Mallow. Normal form. 

 II. Albuco. 12. Lobelia inflala. 13. Compositae, showing one mature and two 

 immature pollen grains. 14. Hibiscus. 15. Pine pollen. 16. Santonica. 17. 

 Mentha species. 18. Hyoscyamus niger. 



Fig. 2. — Potato Starch. — The granules are large and the markings (hili, lamel- 

 lations) are distinct. The cross bands under the polarizer are very distinct. Potato 

 starch, mounted in water, makes a good test object for judging the resolving power 

 of objectives. Dried and ground potatoes and potato parings are sometimes used 

 for adulterating purposes. 



Fig. 3. — Starches. — i. Sago starch from Cycas revoluta (Cycadaceas). The 

 commercial article known as sago is usually in the form of small granules (pearl 

 sago). There are many false sagos made from other than Cycad or Palm starch. 

 Much of this false sago is made from corn starch. 



2. Canna starch from several species of Canna. The markings are very distinct, 

 the hili being at the larger end as a rule. Also called arrowroot {Ions le mois arrow- 

 root). 



3. Cassava or tapioca starch from the tuberous roots of ManihoL utiUissima and 

 other species of Manihot. Simple and compound granules; the granules are largely 

 separated in the processing, thus giving the appearance of simple granules. Their 

 compound origin is, however, recognizable by the contact facets. 



4. Maranta starch (.\rrowroot starch) from Marania arundinacccB (Marantaceas) . 

 The granules have many of the structural characteristics of potato starch. 



5. Yam starch from several species of Dioscorea (Dioscoreacese). 



Fig. 4. — Dextrinized Starch. — The process of baking and cooking causes the 

 starch granules to undergo marked structural changes. They become much 

 enlarged, the outline becomes quite indistinct and the hili and lamellations are 

 distorted and correspondingly indistinct, i. Normal wheat starch granules. 2. 

 Normal rye starch granules. 3. Dextrinized wheat and rye granules. 4. Normal 

 and dextrinized corn starch. 5. Normal and dextrinized bean starch. 6. Normal 

 and dextrinized ginger starch. 



