378 
STRUCTURE AND LIFE HISTORIES 
leaves, but no sporophylls, while the fertile region occurs 
as a clearly recognized cone, formed by the crowding of 
the sporophylls at the apex of the leafy axis (Fig. 273). 
The foliage-leaves are all simple and small (microphyllous) . 
FIG. 273. Lycopodium sp. Photomicrograph of longitudinal section 
of a cone, showing the sporangia on the upper surface of the sporophylls, 
near their insertion on the main axis. 
A more primitive type is found in Lycopodium Selago 
(Fig. 274). Here the lower region is sterile, but is not 
as well developed as in other types, for the sporophylls 
begin to appear lower down on the stem. Moreover the 
sporophylls are not aggregated into a cone, but are dis- 
tributed at intervals from near the base to near the apex, 
