ZEA MAYS 



115 



pi-o CO .•?//• 



teins, and oils contained in the storage and embryonic tissues of the 

 grain. According to Randolph, the antipodal cells frequently 

 proliferate during the 

 development of the cary- 

 opsis, and may persist in 

 the mature grain, form- 

 ing an oval "mass of 

 haploid tissue between 

 the aleurone layer and 

 the pericarp at the tip 

 of the kernel." 



The Embryo. — The 

 embryo lies embedded in 

 the endosperm at one 

 side and toward the base 

 of the caryopsis. (Fig. 

 41.) Its axis is oriented 

 in such a manner that 

 the primary root is di- 

 rected toward the at- 

 tached end of the grain. 

 The scutellum is a large 

 lateral structure lying 

 directly in contact with 

 the endosperm, and its 

 edges partially enclose 

 the embryonic axis. It 

 diverges at the coty- 

 ledonary plate or first 

 node of the seedling 

 axis. The tissue of the 

 scutellum consists of 

 parenchymatous cells ex- 

 cept for the abaxial sur- 

 face, which is covered by 

 a layer of epithelial cells 

 where the scutellum is 

 in contact with the en- 

 dosperm. The occur- 



'Scu no 



— coir 



pri rt 



re 



rence of glands in this node. (After Avery.) 



Fig. 4z. Longisection of the mature embryo of corn: 

 colp, coleoptile; coir, coleorhiza; epith gl, epithelial 

 gland; pri rt, primary root; pro ca str, procambial 

 strand; r f, root cap; sen, scutellum; scu no, scutellax 



