284 



GYMNOSPERMS 



of Selaginclla, or even from that of a eusporangiate homosporous 

 form, like Lycopodium. 'I'here is a hypodermal cell, or layer of cells, 

 which may be called the archesporium. A periclinal division in the 



Fig. 287. — Male sporophylls of conifers: A , Finns laricio; B, Abies grandis; C, Picca 

 alba; D, Cedrus libani; E, Juniperus communis; F, Cryplomcria japoniai; G, Cupressus 

 macrocarpa; II, Agathis australis; I , J, and A', Araucaria ciinninghami; I, view from 

 upper surface; J, view from lower surface; A', transverse section showing 13 sporangia 

 in two rows; all X8. 



archesporium gives rise to two cells or two series of cells, the outer 

 forming the parietal, or wall, layers, and the inner giving rise to the 

 sporogenous tissue. 



