A YORKSHIRE NATURALIST 205. 



was my demonstrator at the Owens College, and, 

 assured of the advantage of his friendly co-operation,, 

 I wrote to M. Van Tieghem, inquiring whether if I 

 sent him a French controversial article dealing with 

 these attacks upon my views by my French friends, 

 he would publish it in the Annales des Sciences 

 Naturelles, of which he was then the editor. He 

 promptly replied that he would publish whatever I 

 chose to send him. 



Thus encouraged, I prepared with the utmost care 

 a review of the positions taken up, more especially 

 by M. Renault, and replied to them seriatim. 

 I placed this manuscript in the hands of Mr. Hartog, 

 who translated it into French. My memoir was flung 

 like a bombshell amongst my opponents. In it I 

 called upon palaeo-botanists of other parts of Europe 

 to take note of my contradictions of many of M. 

 Renault's statements, and of my assertions that our 

 British specimens of carboniferous plants differed 

 absolutely from many of M. Renault's descriptions of 

 the French ones. 



In all such controversies time is an important 

 element. Those who conscientiously hold opposing 

 views on such questions cannot be expected at once 

 to haul down their flags ; they need time to consider 

 and measure the value of facts and arguments 

 advanced by their opponents ; and so it happened in 

 the present instance. The two prominent fossil 

 plants which were the subjects of discussion were 

 the Calamites and the Sigillariae. This demonstration. 



