330 



MICROSPORANGIA 



out into the leaf, whose detailed structure was much like 

 that of many of the simpler Ferns. The root was similar to 

 that of recent plants, possessing from two to eight xylem- 

 groups. 



The microsporangia of Lyginopteris were borne on the under- 

 side of pinnae, with much reduced laminae, and were more or 

 less fused in pairs. The pinna, with its pendant elongated 



FIG. 189. Photograph of transverse section of the stem of Lyginopteris 

 oldhamia (reproduced by the courtesy of Prof. F. \V. Oliver, F.R.S.). 

 Bs., leaf traces ; S., sclerenchyma plates in outer cortex ; Sec., secondary 

 wood ; X., primary xylem strand. 



sporangia, had somewhat of the appearance of an epaulet 

 (Fig. 190). The sporangia produced numerous small spores, 

 which were presumably conveyed by the wind to the ovules, 

 where they became lodged within the pollen chamber. Of their 

 further fate nothing is known, but it is probable that they 

 developed a small male prothallus, giving rise to spermatozoids, 

 somewhat like those of Cycads. 



The ovules arose singly from the ends of truncated branches 

 of the fronds, and showed the same plan of construction as in 



