The President's Address. By Dukinfield H. Scott. 143 



others) that Cryptogams with secondary wood really existed — e.g. 

 in the Calamarian Macrostachya (Not. sur les Calamariees, 1898). 

 In fact, he came to regard both the Sigillariese and the Calamariese 

 as transitional groups between Cryptogams and Phanerogams, some 

 of their members approaching one side and some the other. 

 Though we cannot now accept his conclusions in detail, the broad 

 idea of the existence of such a " debatable land " in the Palaeo- 

 zoic flora is an eminently fertile one. It is a striking fact that in 

 some Lepidodendreae, plants nearly allied to the Sigillarias, but 

 which Eenault would have placed on the Cryptogamic side of the 

 line, organs closely analogous to true seeds have been discovered. 



In his latest work (May 1904) Renault speaks of certain 

 Calamarieae as "Cryptogams with cambium" and thus definitely 

 adopts the Williamson position, though, unfortunately, without 

 recognising Williamson's work in establishing it. At the same 

 time he still inclined to attribute seeds such as Stephanospermum to 

 plants of the Calamarian group. There is no objection in prin- 

 ciple to this conception of the existence of spore-bearing and 

 seed-bearing members of the same family — it is to a great extent 

 realised, as we now know, among the carboniferous Lycopods. In 

 the case of the Calamariese, however, the evidence for the occur- 

 rence of the seed-bearing habit is as yet very inadequate. It is, in 

 any case, a gratification to an English palgeobotanist to realise 

 that, at the close of Renault's career, there was no longer any 

 fundamental difference of view between himself and his fellow- 

 workers in the same field. 



The illustrations of Renault's great work which I have selected, 

 may serve in some degree to indicate his place in the history of 

 science, but are altogether inadequate to give any idea of the extent 

 of his labours. 



Even in the particular field which we have rapidly traversed, 

 investigations of the highest importance have been left untouched, 

 as, for example, his first demonstration of the structure of Spheno- 

 phyllum, representing a wholly extinct class of Cryptogams ; his 

 magnificent investigation of the organisation of Calamarian fructi- 

 fications ; his work on the Cycadoxylese, a family perhaps inter- 

 mediate between Pteridosperms and true Cycads; his detailed 

 anatomical studies on Sigillaria and Stigmaria; and other 

 researches too numerous to mention. 



Besides all this, there is the vast mass of work of his later years 

 on the micro-organisms of Palaeozoic age, to which an incredible 

 amount of labour was devoted. The investigation of fossil Bacteria, 

 at any rate, appears a somewhat thankless task ; in favourable 

 cases, as, for example, that of Bacillus vorax (Renault, 1896, p. 472) 

 occurring in vegetable debris of Lower Carboniferous age, there 

 appears to be no doubt as to the nature of the organism, which 



