September 9, 1898.] 



SCIENCE. 



337 



sumes a knowledge of all the details, but gives 

 some references. The second short chapter is 

 merely introductory, and the third, which is a 

 fairly good resume of the stratigraphical condi- 

 tions, with a columnar section after McKenny 

 Hughes, and a treatment of each formation in 

 ascending order, has the defect of failing to 

 connect the several periods closely enough with 

 the forms of vegetation specially characterizing 

 them. As the treatment in Part II. is botanical 

 and not geological, this could only be done 

 here. A fine opportunity is therefore lost. 



The fourth chapter, treating of the mode of 

 deposition of plants, is excellent and oppor- 

 tune, and is the best summing-up of an obscure 

 but important subject that we have. The 

 author seems to have realized the need of such 

 a survey and has made it correspondingly clear 

 that most of the popular error relating to fos- 

 sils is due to ignorance of their modes of preser- 

 vation in the rocks, and nothing could be more 

 educative than a full and lucid presentation of 

 the facts so far as known. It would be too 

 much to expect this in a work devoted to fossil 

 plants, but any light on the subject is valuable. 

 Here, however, a general knowledge of geology 

 is presupposed, and this chapter, which might 

 well interest many geologists, is not adapted to 

 the needs of the untrained reader. 



The fifth chapter, on the difficulties to be 

 overcome, is very cautiously written and cannot 

 fail to exert a wholesome influence on workers 

 in this field. It proceeds mainly from the usual 

 standpoint of both botanists and geologists, who 

 never tire of emphasizing the unreliability of 

 paleobotanical data. Some excellent examples 

 are given of the possibilities of error, and the 

 author's modest disinclination to defend his 

 cause seems to leave the case with the oppo- 

 nents of the science. This is better than an 

 ardent defence, but he might at least have 

 answered some of the objections that are based 

 on ignorance of the science, and most of the 

 cases are of this class. The errors that have 

 been made are either due to superficial observa-. 

 tion and poor work, or else they are committed 

 by geologists themselves. Of this latter class 

 are most of the instances where ' problematical 

 organisms ' coming from early formations have 

 been referred to the plant kingdom and called 



'fucoids' or 'algas.' It is the geologists and 

 ' paleontologists ' who have done most of this, 

 and the paleobotanists, who came later, merely 

 found them there. They, however, are always 

 held responsible. 



As an illustration of possible carelessness on 

 the part of paleobotanists, we may take the case 

 mentioned by our author on page 97 of the 

 similarity of some Polygonums to Equisetum. 

 He says : "Without a careful examination of 

 the insignificant scaly leaves borne at the nodes 

 this mistake might be made." The answer is 

 that the careful investigator would not overlook 

 these characters, however 'insignificant.' So, 

 too, the case of Kaulfussia, a fern so unlike those 

 with which we are familiar, simply shows the 

 necessity that the paleobotanist acquaint him- 

 self with all kinds of ferns and not be limited 

 to those of his particular neighborhood or 

 country. 



Botanists, acquainted only with plants as 

 they now exist, have, as a general thing, not 

 grasped the meaning of modification with de- 

 scent, although they may often borrow that 

 phrase from Darwin and apply it in a vague 

 sense. They, therefore, have no patience with 

 fossil plants that diflPer considerably from liv- 

 ing ones, and think it foolish to try to name 

 and classify them. When it was discovered 

 that Baiera, which had first been classed as a 

 fern, belonged to the line of Ginkgo, and had 

 to be transferred to the Taxacese, it was thought 

 that the paleobotanists had been guilty of an 

 egregious mistake. But now that Ginkgo has 

 been found to bear antherozoids, and therefore 

 to be much nearer to a fern than to a yew, the 

 mistake is found to have been that of the 

 botanists, while the paleobotanists, in referring 

 it to the ferns, had come much nearer to truth. 



In Part II. the treatment is from the lowest 

 forms upward, but this volume closes long be- 

 fore the Pteridophyta, or Vascular Cryptogams, 

 have been disposed of. In fact, only two classes 

 of them are treated, the Equisetales and the 

 Sphenophyllales. Over 100 pages are devoted 

 to the Thallophyta and only 13 to the Bryo- 

 phyta. Nearly all the classes are briefly treated, 

 whether any of them have been found fossil or 

 not. In a large number, however, fossil forms 

 have been reported, and the field of extinct 



