444 



PART III. — THE CLASSIFICATION OF PLANTS. 



the four anterior octants are octants of a sphere, this is not the 

 case with the four truncated posterior octants abutting on the 

 suspensor. In some cases, the transverse division precedes the 

 longitudinal. From the anterior octants are developed, in Dicotyle- 

 dons generally (Fig. 286), the two cotyledons and the growing- 



FiG, 287.— Embryogeny of Monocotyledons, as represented by Alisma Plantago (diagram- 

 matic, after Goebel, Hanstein, and Famintzin). A-C Successive stages: a embryo-cell; 

 b lowest cell of suspensor, susp. : the products of tbe repeated transverse division of b are 

 indicated (c, d, e,f) in B and C. In C, a has given rise to the single terminal cotyledon ; 

 c to the growing-point of the primary stem ; d and e form the hypocotyl ; the growing- 

 point of the root is developed from/; ep dermatogen. D is a mature embryo, less highly 

 magnified: cot. cotyledon; «t. growing-point of stem; hjp. hypocotyl. The nuclei of 

 the cells are indicated in A and B. 



point of the primary stem, but the growing-point of the primary 

 root is supplied from the last cell of the suspensor (Fig. 286 

 A, a) which divides transversely into two (Fig. 286 B) and con- 

 tributes the cell h, the hypophysis, to complete the root-end of the 



