328 Reviews — Dr. D. Stur — Fossil Ferns of the Coal-measures. 



with sufficient patience for the truth of his generalizations to be 

 tested. Ahhough, however, we must be prepared to find that he 

 made some mistakes, as all enthusiastic pioneers have done in every 

 department of thought, we may still, as Englishmen, feel proud of 

 him, and share the admiration which I have heard Geinitz and others 

 express for him abroad. Personally, I may say that not one word 

 of what I have written has been dictated by any feeling of 

 irreverence for so great a master, or any wish to tarnish the 

 escutcheon of his fame : on the contrary, I have a grateful sense of 

 the privilege which I enjoy, in that it has fallen to my lot to share 

 the friendship of some who were Murchison's greatest friends. 



12, IB AT I IE "V^ S. 



Dr. D. Stur on the Fossil Ferns of the Coal-Measures. 



I. — ZuR Morphologie tjnb Systematik der Culm- und Carbon- 

 FARNE. By D. Stur. (Sitzb. der K. Akad. der Wissensch. 

 Band Ixxxviii. ; 1 Abth. pp. 214, 1883.) 



THIS book, in addition to the observations of previous workers, 

 contains a great deal of original matter on the fructification 

 of Carboniferous fossil ferns, which cannot but be of the greatest 

 interest to all students of fossil botany. 



The systematic arrangement of fossil ferns holds at present a very 

 anomalous position. We have in fact to deal with two distinct 

 systems of classification : those whose fruit is known are generally 

 placed in genera founded upon characters derived from the form, 

 arrangement and structure of the sporangia ; those only known 

 in the barren condition are classified from such characters as are 

 afforded by the nervation and form of the pinnules, and their mode 

 of attachment to the rachis. It has been shown on more than one 

 occasion, that however similar in general appearance the barren 

 fronds of different species may be to each other, such similarity 

 gives no clue by which we can form any estimate of what their 

 fructification may be. Some species of fossil ferns, which in the 

 barren state are so similar that it is with difficulty they can be dis- 

 tinguished from each other, have been found to be essentially distinct 

 when fruiting examples were discovered. Unfortunately, Dr. Stur 

 has placed many species of which the fruit is still unknown in 

 genera whose most important characters are derived from their 

 fructification, thus combining a natural and artificial system (if we 

 may so call it) of classification, — a classification which must be sub- 

 ject to constant change as our knowledge increases. If the barren 

 fronds are kept in genera by themselves, as is at present most com- 

 monly done, it is easy to transfer them to other genera as their fruit 

 becomes known. 



By this plan, much less confusion will be caused than by placing 

 species in restricted genera while we are still ignorant as to whether 

 or not they possess the real generic characters. Unless such a 

 method as this be strictly adhered to, it must inevitably lead to con- 

 fusion and the creation of unnecessary synonyms. 



