364 NATURAL SCIENCE. 



JULY, 



no palaeobotanist maintains that in the Ferns and Coniferae of the 

 Coal-measures we ought not to expect the usual morphological 

 distinctions between the roots and the stems, and until positive proof 

 is adduced to the contrary, it may be fairly assumed that in the fossil 

 Lycopodiaceae such distinctions are not altogether obliterated. If this 

 reasoning be sound, then, whatever truth it may have elsewhere, 

 the contention under discussion can scarcely be applied to explain 

 the absence of all the characteristic root structures from the axis 

 of Stigmaria ficoides. 



It may be submitted, then, that the plant morphologist is within 

 his rights in appealing to the structure of Stigmaria ficoides for 

 assistance in the determination of its morphological nature, and in 

 endeavouring to interpret that structure in accordance with the 

 general laws of plant anatomy. When this is done, it appears, as I 

 have endeavoured to show, that its organisation approaches closely 

 to that of a stem, and has nothing in common with that of a root. 

 Moreover, as we know from observation that it was not aerial, the 

 conclusion is indicated that it is a rhizome. As was intimated at the 

 outset, however, the formal and definitive assertion of this conclusion 

 as an established truth is beyond my present purpose. Hitherto, the 

 upholders of the root hypothesis have not dealt in detail with the 

 facts to which attention has been called, and it remains to be seen, 

 therefore, how far they can reconcile the one with the other. 



REFERENCES. 



1. Dawson, Sir J. W., and Williamson, Professor W. C— Natural 

 Science, May, 1892, pp. 211-216. 



2. Solms-Liaubach, H. Graf zu. — Fossil Botany. Clarendon Press. 

 Pp. 268, 288. 



3. Dawson, Sir J. Iff., and Williamson, Professor W. C. — Natural 

 Science, May, 1892, p. 211. 



4. Williamson, W. C. — Stigmaria ficoides. Palaeontographical Society, 



1887. 



5. Ibid., pp. 13, 15. 



6. Ibid., pp. 30, 31. 



7. Solms-Laubach, H. Graf zu. — Fossil Botany. Clarendon Press. 

 Pp. 277-278. 



8. Tieghem, Van. — Traite de Botanique. 2nd ed. Pp. 689, 1,394 1.423- 

 1.436. 



9. Russow, E:. — Betrachtungen iiber das Leitbiindel-und Grundgewebe, 

 U.S.W., 1875, pp. 45, 46. 



10. Williamson, W^. C. — Stigmaria ficoides. Palaeontographical Society, 



1887, pp. 22-24. 



Thomas Hick. 



