198 



and Hudson Bay regions is valuable; but he must be an ardent 

 believer who can, with complete mental composure, read a de- 

 scription of the lake, swamp, bog, coniferous forest, and deciduous 

 forest formations each seven or more times, the salt marsh, alpine, 

 barren, strand, and dune formations each five times all in the 

 second and third chapters (pp. 360-516), dealing with the vegeta- 

 tion east of the Mississippi and some of its tributaries. Add to 

 this dozens of minor formations, scores of associations, areas, 

 circum-areas, etc., and the indigestibility of the whole mass may 

 be imagined. Granting, however, the suitability of this vast 

 bulk of minutiae in a work on North American phytogeography, 

 the problem has been handled with as much skill, at least as to 

 form, as the almost hopeless nature of the task would permit. 



Some statements challenge attention in this part, as, for in- 

 stance, the assertion (p. 372) that Drosera rotundifolia, Primus 

 pennsylvanica, and Fragaria virginiana are true alpine plants, 

 that Opuntia Rafinesquii is found on Nantucket (p. 380), that 

 Clintonia horealis is a bog plant (p. 385), that Potamogeton Vaseyi 

 and Spirillus are truly Laurentian* in distribution (p. 392), that 

 Sassafras is typically pine-barren (p. 415), and, most important 

 of all, the statement (p. 481) that in West Virginia there is a 

 series of ponds and lakes which represent water-filled kettle-holes 

 of glacial origin! 



The third and fourth chapters of this part continue, with a 

 nearly similar completeness, the description of the vegetation 

 stretching to the Pacific Coast, including the Californian islands. 

 Chapter five considers the Mexican subtropic zone and mountain 

 region, and chapter six, the tropical Mexican and Central Amer- 

 ican regions. The last four chapters (pp. 516-672) are neces- 

 sarily briefer than those dealing with better known regions, but 

 they give a valuable account of their respective areas as we 

 know them to-day. While it is true that our knowledge of the 

 West Indian region is still somewhat limited, we should have 

 expected Dr. Harshberger to have availed himself more fully 



* Both are found within the Laurentian area, but neither is typical of this area, 

 as they are both found far south of it. The citation of Potamogeton distribution 

 as indicative of or resulting from any particular formation, is open to question, as 

 most aquatics may be found far from what is their conjectural center of distribu- 

 tion, and for obvious reasons. 



