August 16, 1895.] 



SCIENCE. 



183 



mind far more valuable to science than the 

 indiscriminate description of new species 

 and genera, and a multitude of such facts 

 would aid very materially in the solution 

 of the origin of species, and the reasons 

 for the gradual change from one type to 

 another. Fbank C Bakee. 



The Chicago Academy op Sciences. 



CURRENT PROBLEMS IN PLANT MORPHOL- 

 OGY (7.) 

 THE QUESTION OF PTEEIDOPHYTE PHYLOGENY. 



If the question be asked : which among 

 living genera of Pteridophytes most closely 

 resembles the hypothetical archetype, three 

 answers are at hand. Goebel, of Munich, 

 adheres to the Prantlian theory that Uy- 

 menophyllwn of the leptosporangiate ferns 

 may be regarded as primitive. The peculiar 

 strength of this position lies in the apparent 

 homologies between the filamentous pro- 

 thallia of this fern and moss-pro tonema 

 such as that in particular of Buxhaumia. 

 Bower, of Glasgow, has brought forward 

 for consideration the curious club moss 

 Phylloglossum and constructs, under his 

 strobilar hypothesis, a phylogeny passing 

 from Lycopodiacese through the eusporan- 

 giate ferns to the leptosporangiate, practi- 

 cally an inversion of the older view. Camp- 

 bell, of Leland Stanford, has argued ably 

 the claims of the eusporangiate fern Ophio- 

 glossum, deriving from its region the Mar- 

 attiace8e,Isoetace8e, Lycopodiaceie and lepto- 

 sporangiate series of ferns. 



The three views may really be reduced to 

 two ; Goebel maintains a leptosporangiate 

 origin for the group ; Bower and Campbell 

 would establish an eusporangiate origin. 

 Therefore one view is quite exactly the con- 

 verse of the other. The peculiar strength 

 of the new position lies in the remarkable 

 sporophytic homologies which have been 

 indicated between Anthoceros of the Hepa- 

 ticse and Marattia and Lycopodium. 



At present the German school labors 



under a certain disadvantage, although the 

 position of Dr. K. Goebel is in accord with 

 the new ideas of mechanomorphosis devel- 

 oped in the rough long ago by Sachs and 

 De Bary and lately carried forward by 

 Sachs, and among zoologists by Eoux, 

 Di'iesch and many others. The disadvan- 

 tage consists in a necessary opposition to 

 the well-established hypotheses of differen- 

 tiation, an opposition in which an actual 

 metamorphosis of embryonic rudiments 

 (Anlagen) is maintained. Bower's theory 

 of sterilization, than which nothing could 

 seem more reasonable under the generally 

 accepted interpretations of ontogenetic and 

 paleontologic records, must be set aside, 

 and, finallj', little use can be made of the 

 remarkable pteridophytic characters of the 

 Anthoceros and Notothylas sporophytes; but 

 one must turn away from this group and 

 bring forward the more specialized mosses 

 as archetypal plants. 



Hugo Gliiek, in Flora SO: 303-387, 1895, 

 under the title Die Sporophyll Metamorphose, 

 gives a valuable census of anatomical re- 

 semblances between sporophylls and foliage 

 leaves, and after an examination of spo- 

 rangial protective apparatus, viz., hairs, 

 pits, indusia, rolled-over margins, etc., of 

 sporophyll petioles, and of various transi- 

 tional forms, proposes as established the 

 thesis that ' all sporophylls are metamor- 

 phosed foliage leaves.' This is almost ex- 

 actly the converse of the Bower- Campbell 

 position which maintains the derivation of 

 non-sporangium-bearing leaves from a spo- 

 rangial tract. The argument of GKick is by 

 no means convincing, for his evidence, ap- 

 parently, might be used with quite as much 

 force on the other side. 



Goebel, carrying the war into Africa, 

 brings out a paper entitled ' On Metamor- 

 phosis in Plants' in Science Progress 3 : 114- 

 126, 1895, which expresses his views tersely 

 and clearly. The outcome of the debate 

 is interesting, for it promises to resolve itself 



