228 



LYCOPODIALES 



[CH. 



seen in fig. 204 ; this is doubtless the expression of a shrinkage 

 of the middle cortical region, which was composed of a delicate 

 and lacunar system of cells. There can be no reasonable doubt 

 that Stigmaria grew in water or in swampy gTound. Specimens 

 are occasionally met with in which the cast terminates in a 

 bluntly rounded apex ; such are, perhaps, young branches which 

 have not- grown far from the base of the aerial stem from which 

 they arose (cf fig. 207, B, C). Other examples occur, such as 

 Goeppert' figured and Gresley^ has more recently described, 





Fig. 205. Stigmaria ficoides. From a specimen in the York Museum, from 

 Bishop Auckland, a, base of rootlet showing vascular bundle scar. 

 M.S. 



which are twisted and distorted as though obstacles had been 

 encountered in the ground in which they grew. 



The circular scars mark the bases of long single and 

 occasionally forked appendages (rootlets) which spread on all 

 sides into the surrounding medium (figs. 20.5, 208). The 

 occurrence of rootlets radiating through the shale or sandstone 

 affords proof that the Stigmarias are often preserved in their 

 position of growth. This was recognised by Steinhauer^ and 

 Logan^ and has been more recently emphasised by Potonie'* as 



Goeppert, loc. cit. 

 Steinhauer (18) A. 



- Gresley (S9) PI. ii. 

 ^ Logan (42). ■'' Potonie (933). 



