SPERMATOPHYTA 



317 



sonia), the two kinds of sporophylls having the same relation to each other 

 as have the stamens and carpels in a flower of the magnolia. Each cone 

 consisted of four sets of members : an outer sheath of sterile bracts, a whorl 

 of microsporophylls, stalked ovules, and interseminal scales (Fig. 26-i). 



In Cijcadeoidea, the microsporangiate structures had advanced but 

 little beyond the fern condition. The microsporophylls (stamens), 10 to 



Fig. 265. Diagram of a longitudinal section of the strobilus of Cycadeoidea, showing hairy 

 bracts below, two pinnate microsporophylls, and the central ovule-bearing axis. {After 

 Wieland.) 



20 in number, were large, leaf-like, and pinnately divided, each division 

 bearing two lateral rows of abaxial sporangia borne in synangia like those 

 of the Marattiales (Fig. 265). The megasporophylls and interseminal 

 scales were closely crowded together at the summit of the strobilus axis, 

 forming a compact ovoid body. Each ovule was borne at the end of a 

 stalk that probably represents a reduced sporophyll (Fig. 266x4). The 

 stalks were more or less vertical, the middle one being the longest. The 

 interseminal scales probably represent sterile sporophylls. The ovule had 

 a basal cupule and a three-layered integument consisting of an outer 

 fleshy, a middle stony, and an inner fleshy layer. The micropyle was 



