180 STUDIES IN FOSSIL BOTANY 



Mr. Maslen in L. oldhamius. The ligule is seated on 

 the upper surface of the sporophyll, near its distal end, 

 and just where the lamina begins to bend upwards. It 

 is a small pointed body, about half a millimetre 

 in height, with a triangular transverse section, and 

 consists of very small-celled parenchyma. In itself it 

 thus resembles the ligule of the vegetative leaves, but 

 differs in the entire absence of any ligular chamber. 

 In allied forms of strobilus, however, a deep ligular 

 chamber is present. As the discoverer points out, " the 

 position of the ligule in Lepidostrobus, with the spor- 

 angium between it and the axis, is identical with that 

 in Selaginella ; but whereas in the latter genus it is 

 quite close to the axis of the cone, in the former the 

 great elongation of the sporangium, which had taken 

 place in the radial direction, had of course carried the 

 ligule with it, and so the latter comes to be situated 

 near the periphery of the cone, and at a considerable 

 distance from the axis. The whole of the horizontal 

 (sporangium-bearing) portion of the sporophyll thus 

 appears to be homologous with the short leaf-base 

 or cushion on the vegetative stem " 1 (see diagram, 



Fig- 71, k\ 



The large, elongated sporangium is seated on the 

 upper surface of the pedicel, to which it is attached 

 throughout almost its whole length, from a point close 

 to the axis, up to the beginning of the lamina (see 

 diagram, Fig. 71). The connection between sporangium 

 and sporophyll thus extends for a long distance in the 

 radial direction, amounting to about a centimetre in 

 large specimens of L. oldhamius, but at the same time 



1 Maslen, Annals of Botany, vol. xii. 1898, p. 259. 



