102 



The subsidence has been so gradual that the marsh grasses have 

 grown uninterruptedly, till in places the roots and dead stalks 

 can be followed from the growing grasses above high tide level 

 to a depth far below the lowest ranges of the tide. The history 

 of the marshes is discussed, their encroachment on fresh water 

 swamps, their change due to bars forming between them and the 

 sea, their burial under dunes, their destruction by changing 

 currents and their reclamation by man. In addition to the 

 definite evidence of slow post-glacial subsidence there is in 

 places fictitious evidence of very recent subsidence, as in the case 

 of drowned forests. It is shown that in many of these cases the 

 forests developed at the edges of swamps and were destroyed by 

 the natural or artificial opening of bars allowing the sea to enter 

 and causing the formation of marshes. When marshes are drained 

 or covered by drifting sand the peat level becomes considerably 

 lower by drying and compression. Very interesting accounts 

 are given of individual marshes along the Loig Island and New 

 England coast and especially of those of the Fundian region. In 

 this latter there is found in one place a forest of stumps, with 

 blackened rootstocks of ferns between, exposed on the side of the 

 bay where it is covered at high tide by thirty feet of water. Ap- 

 parently these stumps extend under the surface of the neigh- 

 boring marsh. Though thousands of years old, the forest was 

 composed of the same species that cover the near-by ridges to- 

 day: — spruce, hemlock, birch, alder, ash, elm and other trees. 



The book is interestingly written, well illustrated with maps, 

 diagrams and photographs, printed on good paper and well 

 bound in cloth. With each chapter there are extended re- 

 ferences to the literature on the subject. While the chief in- 

 terest will be for physiographers, there is much which the botan- 

 ist will find of value. 



George T. Hastings. 



A List of the Plants of El Salvador.* 



The flora of El Salvador, the smallest of American republics, 

 has until recently been as little known as that of any Central 



* Paul C. Standley and Salvador Calderon, Lista Preliminar de las Plantas 

 de El Salvador. 8°, pp. 174, n. d. (published 14 Feb. 1925). Tlpografia La 

 Union, San Salvador, El Salvador. 



