*9 2 FIELD OATS. 



6. The three parts of the fruit : the walls of the ovary 

 and gluten-containing cells ; the starchy part of the 

 grain ; the embryo. 



Study the embryo / note 



7. The long leaf, scutellum, next the starch. 



8. The bud, plumule, near the base of the scutellum, 

 showing one or two leaves. 



9. The root near the base of the embryo, with its root-cap, 

 and enveloped by 



10. The root-sheath ; notice that it is continuous with 



11. The short stem, caulicle, to which the scutellum is 

 attached, bearing the plumule at its upper and the root 

 at its lower end. 



Examine with high power. Note 



12. The tissues of the fruit, essentially as in the trans- 

 verse section. 



13. The tissue of the embryo ; parenchyma with much 

 protoplasm. 



ANNOTATIONS. 



The division of the slender, slowly tapering stem of 

 Avena into ring-like nodes and elongated internodes 

 shows these features distinctly marked for the first 

 time. The disposition of the material in the form of 

 a hollow cylinder gives greater rigidity than would 

 the same amount of material in a solid stem. 



At some of the lower nodes of the stem the endog- 

 enous formation 14 of roots can be well seen, as young 



14 Cf. Prantl and Vines, Text-book, p. 22. 



