132 



sonally chiefly responsible. Segregation is a matter of botanical 

 opinion and can not well be covered by rules. The reviewer be- 

 lieves that such segregation rarely adds anything to our knowl- 

 edge of plant classification and that the segregated groups 

 should be maintained, in most cases at least, only as subgenera 

 or sections. That is certainly the case in Pinns and Pyrola. 

 Segregation invariably means the relegation of otherwise ten- 

 able names to synonymy and often necessitates the creation of 

 new combinations. Under the old American Code the original 

 specific name was almost always carried over into the newly 

 segregated genus, but under the international system this can 

 not always be done. Thus our old friend Pinus Strobus was 

 recognizable under its segregation as Strobus Strobus, but now 

 it becomes Strobus Weymouthiana; we could distinguish the 

 apple in Mains Malus, but as Mains sylvestris its identity is 

 pretty well lost. 



Another class of change in name appears regrettable at first, 

 since it requires us to learn new names for many familiar plants, 

 but really indicates progress in classification and a step toward 

 nomenclatural stability. This rests on the discovery that estab- 

 lished names, often of long standing, have been regularly mis- 

 applied. Naturally we want to keep the old name where it prop- 

 erly belongs and that compels us to learn a new one. Thus we 

 find that the familiar name Actaea alba belongs to a different 

 species and to our common species we must apply the name 

 Actaea brachypoda, while the columbine must be called Aqui- 

 legia latiuscula. Still other changes are caused by the discovery 

 of a prior name for an accepted species. Thus Scrophularia 

 leporella, described by Bicknell in 1896, seems to have been de- 

 tected years before by Pursh and given the name 5. lanceolata. 



The book follows the usual form of a manual. It opens with 

 a key to the families constructed in the usual way. The descrip- 

 tive matter is concise and the larger genera have small illustra- 

 tions of one or more species. Ten pages of abbreviations of au- 

 thors' names, prepared by J. H. Barnhart, give the dates of 

 birth and death. The glossary covers eleven pages. The index 

 is complete. About thirty errata are listed. A summary shows 

 that 3988 species are considered, with the composites, grasses, 

 sedges, and legumes as the largest families, comprising together 

 more than a third of the total. 



