﻿324 MR. E, A. NEWELL ARBER ON" THE [May I905, 



13. On the Sporangium-like Organs of Olossoptebis Bbowniana, 

 Brongn. By E. A. Newell Arber, M.A., E.L.S., P.G.S., 

 Trinity College, Cambridge ; University Demonstrator in 

 Paleobotany. (Eead February 1st, 1905.) 



[Plates XXX & XXXI.] 



Con 



TENTS. 



I. Introduction 324 



II. Description of the Specimens 325 



III. The Morphology of the Sporangium-like Organs 327 



IV. The Evidence for the Attribution of the Sporangium-like 



Organs to Glossopteris 329 



V. The Morphological Nature of the Sporangium-like Organs. 330 

 VI. Historical Sketch of the present Evidence as to the 



Fructification of Glossopteris 332 



VII. General Conclusions 334 



VIII. Bibliography 336 



I. Introduction. 



Glossoptebis is now among the most familiar of all fossil plants. 

 The tongue-shaped fronds of this genus, with their reticulate 

 lateral nervation, are exceedingly characteristic of the Permo- 

 Carboniferous rocks of India, Australasia, and Southern Africa, 

 and occur also in the Permian of Russia, and in beds of Rhaetic 

 age in Tongking and China. So great is the abundance of these 

 fern-like leaves in the Lower Gondwana Series of India, and its 

 homotaxial equivalents in the Southern Hemisphere, that this 

 plant has given its name to the flora of that former continental 

 region. 



Although a very large number of Glossojrteris-honds have been 

 described by different authors, it is only within the last few years 

 that we have learnt anything as to the general habit of this plant. 

 We are chiefly indebted to the researches of Prof. Zeiller, of Paris, 

 for progress in this respect. It has now been ascertained that this 

 plant was heterophyllous, 1 — a fact which was first suggested by 

 M'Coy in 1847. 2 In addition to the larger and often tongue- 

 shaped fronds, much smaller leaves, generally spoken of as scale- 

 fronds, were borne on a rhizome-like stem, which has been long 

 known under the name of Vertebraria. 3 The nervation of the 

 scale-fronds resembles that of the larger leaves, except that there 

 is no midrib. In shape they are, as a rule, ovately triangular, 

 pointed at the apex, and strongly concave. An average specimen 

 measures 1| centimetres or more in length. 



1 Zeiller (96 1 ) p. 365. [Numerals in parentheses after authors' names refer 

 to the dates in the Bibliography, §viii, p. 336.] 



2 M'Coy (47) p. 151 ; see also Arber (02) p." 9. 



3 Zeiller (96 2 ) and Oldham (97). 



