Periodical Literature. 727 



types. Typical trees of the humid hardwood forests are ma- 

 hogany, cigarbox cedar, silk cotton tree, royal palm, walnut, Pinus 

 occidentalis, Xanthroxylueni and "oak" (Tecoma). Bayahonda, 

 campeche, mahogany, dividivi, and lignum vitae are characteristic 

 of the dry hardwood type while the pineries consists of pines and 

 a juniper (/. barbadensis Lam,)- These types contain eleven 

 billion feet of hardwoods and three billion feet of pine with a 

 total value of nearly twelve million dollars. Lack of roads 

 renders it impossible to realize this value at the present time. 



Wood exports amounted to $150,000 in 1910 of which lignum 

 vitae contributed more than half and mahogany about nine per 

 cent. England was the largest customer while the United States 

 bought a little less. Ten per cent, went to Germany. 



Nutsholzbestdndc in der Dominikanischen Republik. Silva. January, 

 1912. Pp. 21-2. 



Watson has reported upon several years of 

 Plant study in the region where the 35th parallel 



Associations crosses New Mexico. The altitude of the 



of region extends from approximately 5,000 



North Central feet in the valley of the Rio Grande to 

 New Mexico. 11,000 feet on the Sandia Mountains. The 

 topographic forms include: a river vallev 

 composed of beds of adobe clay, sand and gravel ; a gradually slop- 

 ing plain of stream origin consisting of ancient gravels and clays 

 intermixed with sand fans and other detritus resulting from the 

 weathering of the mountains ; mesas, sometimes covered by a lava 

 flow so recent that it has suffered almost no weathering, the 

 shallow soil covering them to the depth of a few inches having 

 been deposited by wind; other mesas composed of archean 

 granites and gneisses capped by carboniferous limestone ; moun- 

 tain slopes ; dry stream valleys and canyons. 



With the exception of the cottonwood association in the river 

 valley, no tree associations are encountered until the slopes of 

 mountains, or sometimes the higher mesas (6,500 ft. or over) are 

 reached. The first of these is the cedar formation (Juniperus 

 monospernta). Contrary to most of authors, the writer seperates 

 this from that next above, the pinon formation. The pinon 

 (Pinus edulis) never extends as far down the mountain side as 



