,s,, SIGILLARIA AND STIGMARIA. 213 



conical tap roots springing from the lower sides, but nothing rising 

 from the top, except where a Sigillavia stem crowns the meeting of 

 its four or eight main roots. 



6. The objection to calling the StigmavicB roots and their 

 processes rootlets, appears to me a finical application of modern 

 botanical usages to times for which they do not hold. We might 

 equally object to the application of the term roots to those which 

 spring from the earthed-up stems of Calamites, radiating as they do 

 from nodes which, in the air, would produce branchlets. Grand' 

 Eury's figures show abundant instances of this. We might also 

 object to the exogenous stems described by Williamson, which belong 

 to cryptogamous plants, and, unlike anything modern, are made up 

 exclusively of scalariform tissue. If the articulation and regular 

 arrangement of those gigantic root-hairs, the rootlets or leaves of 

 Stigmavia, are to be regarded as depriving them of the name which 

 clearly describes their function, we may call them underground 

 branches, though, by so doing, we set at nought both their function 

 and their mode of growth. 



7. The above remarks show, so far as they go, how completely 

 the doctrine of Stigmavia-vindercXaLys and the terrestrial growth of 

 coal, as originally explained by Sir William Logan, are borne out by 

 the facts ; and I may refer, in further illustration of this, to the 

 remarkable history of the erect Sigillari^, containing remains of land 

 animals at the South Joggins, as given in my memoir on erect trees 

 containing animal remains. ^ 



In making the above statements, I would not be understood as 

 derogating in the least from the merits of my esteemed confrere, 

 M. Grand' Eury. His work on the Carboniferous Flora of the 

 Department of the Loire, and the later work above referred to, are 

 triumphs of that careful and elaborate exploration of fossil plants 

 in situ which, while most laborious and difficult, gives us the only 

 certain means of restoring, in their integrity, the plants of the old 

 coal forests. No labourer in this arduous field deserves greater 

 credit than Grand' Eury ; but, to obtain their full benefit, the results 

 of his labours require to be compared with those of others in different 

 localities, and to be interpreted, not on the Umited rules of modern 

 botanical nomenclature, but in accordance with wide views of the 

 versatile methods of nature, more especially in the older periods of 

 the earth's history. 



J. William Dawson. 



■■' Phil. Trans., 1882, pp. 621-659. I may also refer to a paper by Wild in the 

 last number of the Trans. Geol. Soc, Manchester, vol. xxiv., pt. 13 (1892). 



