THE PLANT WOELD 39 



relationships of tlie genus in question, to say nothing of figures of the 

 species, extended keys and diagnoses, and the most detailed measure- 

 ments of the individual parts of a plant. Such a work is the logical 

 outcome of the modern doctrine of "expansion " as applied to botanical 

 taxonomy, and without this very comjilete literature of the subject, it 

 would be impossible for all but actual specialists to identify the species 

 of difficult genera. 



The new monograph of Professor Coulter and Dr. Rose is typical 

 of this progressive spirit. The work begins with a complete bibliog- 

 raphy of the subject, arranged in three distinct periods ; then follows a 

 list of the new species described since the i)ublication of the " Revision 

 of North American Umbelliferae " by the same authors in 1888 ; a con- 

 spectus of the native and introduced genera ; and a list of post-Linnaean 

 genera based on a single species. Passing to the text of the book, the 

 reader will be quick to notice and appreciate the illustrations of en- 

 larged fruits and fruit-sections, placed in each case in juxtaposition 

 with the generic descriptions to which they pertain. The specific diag- 

 noses, in addition to a full statement of synonomy and geographic 

 range, include a citation of the type locality and a large share of the 

 specimens examined by the authors. 



We fear that our more conservative friends will experience a slight 

 shock when they observe the lavish liberality "udth which generic lines 

 are drawn by Messrs. Coulter and Rose. The most notable illustration 

 of this may be seen in the expansive tendency of the original Cj/mop- 

 teriis, which has now developed into Cymopterus, Glehnia, Phellopterus, 

 Pteryxia, Aulospermum, Rhysopferus and Pseudocymopterns. Yet even 

 a casual examination of fruit characters in these different genera, as 

 displayed in the text figures, must convince the reader that they rest 

 on a substantial natural foundation. 



With the exception of the few inevitable typographical errors, the 

 reviewer will find this work almost without defects, and in the writer's 

 opinion it is the most complete and satisfactory presentment of a fam- 

 ily that has come to the attention of latter-day botanists. — C. L. P. 



A Monograph of the Erysiphaceae. By E. D. Salmon, F. R. S. Me- 

 moirs of the Torrey Botanical Club, Vol. IX. 



This is one of the most important of recent contrilnitions to syste- 

 matic mycology. The author, who did most of his w^ork at Kew, has 

 had unusual facilities in the way of exsiccata and literature, and has 

 treated his subject in a thorough and comprehensive manner. Follow- 

 ing the introduction is a chapter on "Morphology and Life-History," 

 in which is brought together the latest results of investigations along 

 these lines. Next a short history of previous systematic studies of 



