SPEBMAPHYTES. 



147 



lower side, and pale green with purplish blotches above. The 

 epidermis may be very easily removed, and is perfectly color- 

 less. Examined closely, longitudinal rows of whitish spots 

 may be detected : these are the breathing pores. 



A cross-section of the stem shows numerous whitish areas 



,-sp. 



FIG. 81. A, plant of the yellow adder-tongue (Erythronium americanum), 

 x Vs. B, the bulb of the same, x %. r, roots. C, section of B. st. the base 

 of the stem bearing the bulb for next year (6) at its base. D, a single petal 

 and stamen, x %. /, the filament, an. anther. E, the gynoecium (pistil), 

 x 1. o, ovary, st. style, z, stigma. F, a full-grown fruit, x %. G, section 

 of a full-grown macrosporangium (ovule), x 25 : i, n, the two integuments. 

 sp. macrospore (embryo sac). //, cross-section of the ripe anther, x 12. /, a 

 single pollen spore, x 150, showing the two nuclei (n, n'). J, a ripe seed, 

 x 2. K, the same, in longitudinal section, em. the embryo. L, cross-section 

 of the stem, x 12. fb. fibro-vascular bundle. M, diagram of the flower. 



scattered through it. These are the fibro-vascular bundles 

 which in the monocotyledons are of a simple type. The bulb 

 is composed of thick scales, which are modified leaves, and on 

 cutting it lengthwise, we shall probably find the young bulb 

 of next year (Fig. C, b) already forming inside it, the young 



