38 



Floristic plant geography, 30 pages; Part 3, Ecological plant 

 geography, 192 pages; Part 4, Relation of natural vegetation 

 to crops, 9 pages; Part 5, Agricultural features, 53 pages; Part 6, 

 Forests and their products, 17 pages; and Part 7, List of plants, 

 114 pages. In all of these parts a three-fold division of the 

 state on physiographic grounds (and not climatic, as one might 

 be led to expect from the auspices under which the book ap- 

 peared) into coastal zone (coastal plain), midland zone (meta- 

 morphic or crystalline rocks), and mountain zone (Alleghany 

 plateau) is recognized. The coastal zone is further subdivided 

 by Chesapeake Bay into two perceptibly different parts, and the 

 midland zone into lower and upper (or foot-hills and ridges), 

 corresponding with the Piedmont region and Blue Ridge of the 

 states farther south. 



Part I, by Dr. Shreve, outlines the scope of the work, making 

 a sharp distinction between floristic and ecological plant geog- 

 raphy (a point which deserves more attention than has been 

 given to it in the past), and then discusses the climatology, 

 topography, mineralogy, and soils of the state. 



Part 2, also by Dr. Shreve, opens with a brief sketch of the 

 history of botanical exploration in Maryland, up to the time 

 when the present authors took the field. Then follow lists of 

 plants which are supposed to be confined to a single zone or to 

 two adjacent zones, plants which reach their northern limits on 

 or near the Delaware peninsula, strand plants, salt-marsh plants, 

 pine-barren plants which seem to skip Maryland, etc. If the 

 systematic list (part 7) represents fully the authors' knowledge 

 of the local distribution of plants within the state, then some 

 of the zonal lists might have been considerably modified or 

 extended. But discrepancies of this kind are almost inevitable 

 in such a large book, in which considerable time must elapse 

 between the writing of the various parts. Kearney's table of 

 the northern limits of " austroriparian " plants, although men- 

 tioned approvingly in a footnote on page 93, was apparently 

 not utilized to the utmost in preparing the list of plants whose 

 northern limits pass through Maryland. The list of "pine- 

 barren" plants which are not known between New Jersey and 



