SPERMAPHYTES. 89 



and find the organ of absorption (scutellum) 

 enclosing the rest of the embryo and in 

 close contact with the endosperm. 

 Dissect out the parts enclosed by the scutellum. 

 Observe : 



(a) The radicle directed toward the small end 



of the grain, and the root-sheath covering 

 its free end. 



(b) The plumule at the opposite end of the 



embryo. Its outer leaf is the cotyle- 

 don. 



(c) The caulicle, the attachment between the 



scutellum and the rest of the embryo. 

 3. With a razor make a median longitudinal section 

 through the broad sides of a grain. Observe 

 on the cut surface : 



(a) The tough outer membrane, composed of 



the united coats of the fruit and the 

 seed. 



(b) The endosperm, consisting of starch and 



other food-materials. 



(c) The embryo, with its organ of absorption, 



the scutellum. 



Sketch the section much enlarged. 

 YL Wheat, 



Examine the seed entire, and then find the 



parts of which it consists. 

 Sketch. 



