LllVNEAN SOCIETY OF LOKDOX. 77 



Among discoveries of special botanical value, in addition to 

 the iniportuut work on the fructiiication of fossil Perns, already 

 alluded to, may be mentioned Zeiller's discovery of the cones of 

 ShjUlaria (18^54-), which for the tirst time definitely proved the 

 Cryptogamic nature of these plants and their close relationship 

 to Lepldodendron. Not less important was his demonstration of 

 the structure of the fructification of Si>henopluillum (1893), a 

 remarkable example of the correlation of evidence from carbon- 

 aceous impi'essions with that from petrified specimens. The 

 recognition of Vertthraria as the rhizome of Glosfopteris (189(5) 

 is another of his botanical results. The mention of Ghssopteris 

 recalls his valuable essay on the differentiation of Botanical 

 ])rovinces at the close of the Palaeozoic Period, a time when a 

 clear distinction between a North.ern and a Southern Flora mani- 

 fested itself, while, both before and after, the vegetation of the 

 world showed a remarkable uniformity. 



The discovery that so many of the so-called Carboniferous 

 Perns were in reality seed-bearing plants (Preridosperms) found 

 a generous recognition from Zeiller, who was the first to bring 

 the new results before the Preiich Academy (1901), In a subse- 

 quent essay (1905)* he gave a critical account of the whole 

 question, which is still the best we possess. 



The fine monograph on the famous fossil Lepidostrohtis Brownii 

 (1911) t completely clears up the relationships of this fructi- 

 fication, of which Zeiller determined the Lower Carboniferous age. 



As regards the broader questions involved in palaeontological 

 studies, Zeiller was a thorough evolutionist, but not a Darwinian, 

 for he was a believer in abrupt changes (mutations or rather 

 saltations) leading at once not merely from species to species 

 but even from group to group J. Though, in the opinion of the- 

 writer, he went too far in this direction, Zeiller undoubtedly did 

 good service to Science in dwelling on the immense difficulties 

 and complexities which still stand in the way of a continuous 

 phylogeny of fossil forms. 



Among Zeiller's more general works may be mentioned his 

 'Elements de Palcobotanique' (1900), an admirable text-book, of 

 which a second edition m ould have been most welcome ; his 

 masterly summaries of palseobotanical progress during 20 years 

 (1886-190(3) § ; and, lastly, his valuable sketch of advances in 

 Mesozoic Palteobotany (]907)||. 



Zeiller's merits were recognised in this country by the Hono- 

 rary Degree conferred upon him by the University of Cambridge 



* " Une iiouvelle Classe de Gymnosperines — k^s l*teridospei-mees." Kevue 

 Gen. des SciencPs, August 30, 1905. 



t Etufe sur le Lepidosirobus Brownii. Paris, 1911. 



\ See especially " Les Vegetaux Fossiles et leurs Euchaiiiemeiits." Eevue 

 dn Mois, February 10, 1907. 



§ Paleontologie Vegetale. 1886-1893 in Anr.uaire Gt'ol. Universol, Tomes 

 iii-x. 1893-1896 in Revue Gen. de But., Tomes ix, x. 1897-190U ibid., 

 Tome XV. 1900-190() ibid., Tomes xv, xvi. 



II "Los Pr )gr',''s de la I'Mleohotaniquc de I'cre des Gymnospcrmcs." 

 Proj^ressus Rei Botaiiiciu, Vol. ii. Part 1. 



