58 PHARMACEUTICAL BOTANY 



develops within it a plumule, the cotyledon withers, and the young 

 plant (seedling) passes the following winter in this condition. 



During the next spring the plumule develops into a foliage leaf and 

 the bulb gives rise from its base to several slender elongated runners, 

 which, at their tips develop runner bulbs. These runner bulbs, the 

 third year, give origin to another set of runners similar to those 

 formed during the second year which also develop runner bulbs at 

 their tips. A foliage leaf is also formed by each. The following 

 spring (spring of fifth year) one of these bulbs develops into a 

 mature sporophyte plant, bearing a single flower at the summit of 

 its elongated scape. See Fig. 27. 



RESEMBLANCES BETWEEN GYMNOSPERMS AND ANGIOSPERMS 



1. In both are developed those structures in which there is no 

 homologue, e.g., flowers. 



2. In both the flowers develop at least two sets of leaves (either 

 on one or two plants of the same species) called sporophylla or 

 sporophyll leaves, the stamens and carpels. The stamens or stam- 

 ina! leaves are also termed microsporophylls. The carpels or 

 carpellate leaves are also known as megasporophylls. 



3. Both groups produce microspores or pollen grains and mega- 

 spores or embryo sacs. 



4. In both are developed on the evident generation, the plant or 

 sporophyte and the gametophyte, the latter concealed within the 

 megaspore of the sporophyte. 



5. Both develop seeds with one or two seed coats. 



6. In both groups there is developed from the fertilized egg an 

 embryo which lies within the cavity of the megaspore. 



7. In both there exists a root and a stem pericambium. 



8. Both produce collateral vascular bundles. Very rarely do we 

 meet with concentric bundles in the stem or leaf of Angiosperms. 



FUNDAMENTAL DIFFERENCES BETWEEN GYMNOSPERMS AND 

 ANGIOSPERMS 



i. The flowers of Gymnosperms are often monoecious or dioecious 

 but very rarely hermaphrodite, as in Welwitchia, whereas those of 

 Angiosperms are usually hermaphrodite, rather rarely monoecious, 

 still more rarely dioecious. 



