STRUCTURE AND GERMINATION OF SEEDS 31 



paper, and others in coco-nut fibre. Compare dry and 

 soaked grains as to size and shape. A grain of wheat 

 (Fig. 12) is the product of the pistil, and is a fruit, not 

 a seed. The fruit-coat and the seed-coat, however, adhere 

 firmly, and cannot be easily distinguished. The outer 

 fruit-coat, or pericarp, is smooth, grooved on one side 

 (Fig. 12, 1) and convex on the other (2). Note the tuft of 



Pi. 



G. 



ep. 



Fig. 13. Vertical Section of Wheat Emeryo. a.r, adven- 

 titious root ; e, endosperm ; ep, epithelium of the scutellum ; /, 

 ligule ; PI, plumule ; ra, radicle ; r.c, root-collar ; sc, scutellum. 



hairs at one end, and at the other an oval area in which 

 is a small wrinkled body (em). Cut the grain in two along 

 the groove and apply a drop of iodine solution to the cut 

 surface. Do all parts stain equally ? The little struc- 

 ture at the end is unstained. This is the embryo. The 

 parts of which it is composed can be well made out on 

 examining soaked grains with the aid of a pocket lens. 



