438 THE CARBONIFEROUS SYSTEM. 



for Conifers, and their resemblance to the fruits of Salishurija gives 

 countenance to this claim ; but the Conifers of the Coal period are 

 much too few to afford more than a fraction of the species. One 

 species of Rhabdocarpus has been attributed by Geinitz to the genus 

 Noeggerathla ; but the leaves which he assigns to it are very like those 

 of Sigillajna elegans, and may belong to some allied species. With 

 regard to the mode of attachment of these fruits, I have shown that 

 one species, Trigonocarpum racemosum of the Devonian strata,* was 

 borne on a rhachis in the manner of a loose spike, and I am convinced 

 that some of the groups of inflorescence named Antholitlies are simply 

 young Rhabducarpi or Trigonocarpa borne in a pinnate manner on a 

 broad rhachis and subtended by a few scales. Such spikes may be 

 regarded as corresponding to a leaf with fruits borne on the edges, in 

 the manner of the female flower of Cycas ; and I believe with Golden- 

 berg that these were borne in verticils at intervals on the stem. In 

 this case it is possible that the strobiles described by that author may 

 be male organs of fructification containing, not spores, but pollen. 

 In conclusion, I would observe that I would not doubt the possibility 

 that some of the fruits known as Cai-diocarpa may have belonged to 

 sigillai'ioid trees. I am aware that some so-called Cardlocarpa are 

 spore-cases of Lepidodendron ; but there are others which are mani- 

 festly winged nutlets allied to Trigonocarpum^ and which must have 

 belonged to phtenogams. It would perhaps be unwise to insist very 

 strongly on deductions from what may be called circumstantial evi- 

 dence as to the nature of the fruit of Sigillaria ; but the indications 

 pointing to the conclusions above stated are so numerous that I have 

 much confidence that they will be vindicated by complete specimens, 

 should these be obtained. 



All of the Joggins coals, except a few shaly beds, afford unequivo- 

 cal evidence of Stigmaria in their underclays ; and it was obviously 

 the normal mode of growth of a coal-bed, that, a more or less damp 

 soil being provided, a forest of Sigillaria should overspread this, and 

 that the Stigmarian roots, the trunks of fallen Sigillarice, their leaves 

 and fruits, and the smaller plants which grew in their shade, should 

 accumulate in a bed of vegetable matter to be subsequently converted 

 into coal — the bark of Sigillaria and allied plants affording " bright 

 coal," the wood and bast tissues mineral charcoal, and the herbaceous 

 matter and mould dull coal. The evidence of this aftbrded by micro- 

 scopic structure I have endeavoured to illustrate in a former paper. -j- 



The process did not commence, as some have supposed, by tlie 



* "Flora of the Devonian Period," Quart. Journ. Geol. Soc, vol. viii. p. 324:. 

 t " On the Structures in Coal," Quart. Journ. Geol. Soc. 1859. 



