306 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



This scheme is of the greatest possible interest since Goebel, though not pri- 

 marily a taxonomist, is one of the earliest professed evolutionists to consider 

 taxonomic problems in their broader aspects; he is also one of the very first to 

 include the fossil groups as part of a scheme involving living plants. In Eng- 

 land the first inclusion of fossils in a botanical text is in the notes added by 

 Vines to the second English edition of Sachs's Textbook published in 1882. 

 When we realize further that certain groups, such as the Sphenophyllales, were 

 still very imperfectly known (first observations on anatomy, Renault and Zeil- 

 ler, 1870-1873; Williamson, 1874) and that as late as 1881-1886 Sphenophxjl- 

 lum was interpreted by Renault himself as a member of the Rhizocarpeae related 

 to Salvinia, the modern tone of Goebel 's scheme is very impressive. It is also 

 of interest to notice that by including the gymnosperms and angiosperms in 

 one coherent scheme with the Pteridophyta, Goebel is in fact expressing phy- 

 letic views about their origin which, in the text of his paper, he discusses some- 

 what more explicitly. The leptosporangiate ferns he regards as so different from 

 seed plants as to be in no sense ancestral to them, and the correlation between 

 an indusium and an integument or between the sporangium and a nucellus can 

 therefore be an analogy only; a highly instructive comment on current usage 

 since Hofmeister. Goebel's views on the origin of seed plants are also interest- 

 ing. He derives the conifers from the l.ycopods and the cycads from Marattia- 

 ceae, both Eusporangiate groups. These views are no longer held by any botan- 

 ist, but it is doubtful whether anything better could have been suggested on 

 the evidence available in 1881. 



In 1881, the most conspicuous void in knowledge regarding the pteridophytes 

 was that of vascular anatomy. It is true that in 1877 De Bary's Vergleichcnde 

 Anatomie der Y egetationsorgane der Gefdssflanzen had appeared belatedly as the 

 last volume in a comprehensive textbook originally planned in 1861 to cover the 

 whole of botany under the editorship of Hofmeister, a project which had been 

 much impeded by the successive deaths of all the original contributors except 

 Sachs and De Bary. This book, however, is of greater intrinsic significance in 

 the history of flowering-plant anatomy than it is for the vascular cryptogams. 

 Interest in plant anatomy in general was undoubtedly stimulated by it and it 

 is still a valuable source of reference for teaching purposes. But for the Pteri- 

 dophyta it may be suspected that its greatest effect may have been indirect, 

 by focusing the attention of the young F. 0. Bower on the need for further ex- 

 ploration of the vascular structure of this group in the course of translating 

 the text. This translation, in collaboration with D. H. Scott, for the English 

 edition of 1884, appeared under the title, Comparative Anatomy of the Phane- 

 rogams and Ferns. 



Ahnost concurrently with this we have the publication of van Tieghem's 

 Traits de Botanique, 1884 (2d ed., 1891). This great French textbook has never 

 received the publicity accorded to the German textbooks of Sachs and later of 

 Strasburger (1894) but it stimulated and expressed the work of an important 

 school of French plant anatomists. To van Tieghem himself we owe the intro- 

 duction of the concept of the stele (van Tieghem and Douliot, 1886), without 

 which the descriptive exploration of the Pteridophyta is impossible. The ap- 

 plication of this concept to the Pteridophyta was in part explored by van Tieg- 

 hem's own school (cf., for example, the Traite, 2d ed., 1891; van Tieghem, 



