8 HISTORICAL SKETCH. [CH. 



of an extensive vegetation occurred in the Carboniferous series ; 

 and from a recent examination of the mountain-limestone 

 groups and coal-fields of Scotland, and the north of England, 

 we learn that these early vegetable productions, so far from 

 being simple in their structure, as had been supposed, are as 

 complicated as the phanerogamic plants of the present day. 

 This discovery necessarily tends to destroy the once favourite 

 idea, that, from the oldest to the most recent strata, there has 

 been a progressive development of vegetable and animal forms, 

 from the simplest to the most complex^" Since Witham's 

 day we have learnt much as to the morphology of Palaeozoic 

 plants, and can well understand the opinions to which he thus 

 gives expression. 



It would be difficult to overrate the immense importance of 

 this publication from the point of view of modern paleobotany. 



The art of making transparent sections of the tissues of 

 fossil plants seems to have been jfirst employed by Sanderson, 

 a lapidary, and it was afterwards considerably improved by 

 NicoP. This most important advance in methods of examina- 

 tion gave a new impetus to the subject, but it is somewhat 

 remarkable that the possibilities of the microscopical investi- 

 gation of fossil plants have been but very imperfectly realised 

 by botanical workers until quite recent years. As regards such 

 a flora as that of the Coal- Measures, we can endorse the 

 opinion expressed at the beginning of the century in reference 

 to the study of recent mosses — " Ohne das Gottergeschenk des 

 zusammengesetzten Mikroskops ist auf diesem Felde durchaus 

 keine Erntel" A useful summary of the history of the study 

 of internal structure is given by Knowlton in a memoir 

 published in 1889 ^ Not long after Witham's book was issued 

 there appeared a work of exceptional merit by Corda^ in which 

 numerous Palaeozoic plants are figured and fully described, 

 mainly from the standpoint of internal structure. This author 



1 Witham (33), p. 5. 



2 Nicol (34). See note by Prof. Jameson on p. 157 of the paper quoted, to the 

 effect that he has long known of this method of preparing sections. 



3 Limpricht (90) in Rabenhorst, vol. iv. p. 73. 



4 Knowlton (89). s Corda (45). 



