48 



LYCOPODIALES 



[CH. 



(fig. 127); each sporophyll, which is supplied with a single vascular 

 bundle, has a large mucilage-cavity {m) in its lower region. 

 " The mucilaginous change " in the sub-sporangial portion of 

 a sporophyll " extends to the surface involving the epidermis, so 

 that this portion of the sporophyll-base may be described as 

 consisting of a mass of mucilage bounded below by a structureless 

 membrane^." Dehiscence of the sporangia occurs at the middle 

 of the distal face (fig. 127, a;). As seen in the radial section 

 (fig. 127, ma) the outer margin of the base of the sporophyll 

 bears a short outgrowth. The leaf-bases of each whorl hang 

 down between the sporangia of the alternating whorl below, and 



Fig. 128. Transverse section of the cone of Lycopodium cemuum, in its plane 

 AA of fig. 127. (After Lang.) 



the base of each sporophyll is coherent with the margins of the 

 two sporophylls of the next lower whorl between which it lies, 

 the sporangia being thus closely packed and lying in a 

 pocket " open only on the outer surface of the cone." Fig. 128 

 represents a transverse section through a cone in the plane AA 

 of fig. 127 ; this traverses the sporangia and their subtending 

 bracts (b) of one whorl and the dependent bases of the 

 sporophylls of the next higher whorl in the region of the 

 mucilage-sacs (m), which are bounded at the periphery by the 



>■ Lang (08) p. 357. 



