I'28 



VASCULAR CRYPTOGAMS 



above that ; thus giving a remarkable superficial resemblance to a fir- 

 cone. The sporophylls of each whorl are not united with one another ; 

 they resemble those of Equisetum in their peltate form, and each bears 

 on its under side four sporanges. It is very rarely that the spores are 

 preserved in sufficient perfection for their structure to be made out with 

 certainty. The statement that they are of two kinds, megaspores and 

 microspores, rests on insufficient evidence. Carruthers believes that he 

 has detected in a few cases an outer separable membrane which would 



FIG. 100. A, Fructification of Cingularia typica; B, portion of a barren and of a fertile whorl 

 C, upper surface of fertile whorl. (After Weiss.) 



unroll itself in the form of elaters. In Palaeostachys (Weiss) the spo- 

 rophylls stand in the axils of the barren leaves. The fructification of 

 Cingularia (Weiss) has a very remarkable appearance, from the alternate 

 barren and fertile whorls standing out nearly at right angles to the axis ; 

 the leaves of the barren whorls are connate for about half their length ; 

 the sporophylls are also united in each whorl into a horizontal plate, 

 divided at the margin into truncate lobes ; from the under side of this 

 plate the sporanges hang vertically in radial rows. The remains of 

 Cingularia fructifications are found in large numbers in the coal 



