66 



PLANT LIFE. 



(see fig. 76). Ill many of the seed-plants the egg divides 

 several times in parallel planes, forming a 

 short filament, the suspensnr {f\\ifi. 79-82). 

 The terminal cell of this row may then 

 gi\e rise to an embryo, as just descriljed, 

 ox this terminal cell and an adjacent one 

 mav take part in forming the embryo. In 

 this case the terminal cell, bv its di^■isions, 

 either produces the p)riniary leaf or leaves, 

 —A very young qj. j (- iiroduces the primary stem and 



o ot the onion. ' ^ ^ 



J, «, cells of the siispen- Jeaves ; while the second cell gives rise to 



sor; rt, a, b, cells from ^ 



which the embryo de- ti-,g primary stem and root, or to the 



velops. Highly inagni- r j ' 



lied.— After Sachs. primary root aloiic (see figs. 80-82). 

 The two primary members formed 

 from the root hem isj there of fernworts 

 are not always permanent. The foot is 



Fic;. 79 

 embry 



Fig. 80. Fig, 8i. 



Fig. 80.— a very yoimg enibryo of shepherd's-purse. Snspensor, j-, j-. 

 and first four ceils of embryo formed by division of terminal one ■" 

 /', is to produce part of the root. Highly magnified.— After Hanstci 



Fig. 81.— An older stage of the same. E, embryo; I,' , i", two cells 

 division of t. fig. 80 ; j. s. snspen.sor. The .shaded cells produce til 

 vascular bundles Highly magnilied. — After Hanstcin. 



Fig. 82. — An older embryo of same. jT, embryo: A /, primary lea\-i 

 stem ; r, primary root ; ;-,-. first layer of root-cap; .v, suspensor. Y". 

 in part. Less magnilied than preceding —Alter Hanstein. 



