388 BOTANICAL GAZETTE [May 
and are fully discussed in his work on the Indo-Malay strand 
flora and alsoin his recent Plant Geography. In the latter work 
there are several excellent discussions of sand dune vegetation, 
. accompanied by photographs from a number of regions, The 
tropical dunes have totally different species, but even there the — 
dominant dune-formers are grasses with the same life habits as 
Ammophila. 
Dunes may be formed in deserts and inland regions apart 
from large bodies of water. Those in the Sahara and in the 
deserts to the northeastward have been more or less studied. 
Brackebusch has described dunes in Argentina. 
In the United States dunes are common along the Atlantic 
coast, especially in Massachusetts, New Jersey, North Carolina, 
and Florida. On the Pacific coast they also occur extensively. 
None of these marine dunes have been exhaustively studied 
from the ecological standpoint. One of the best works that has 
ever appeared on strand floras is that by MacMillan on the 
shores at the Lake of the Woods. The dune formation is not 
extensive there, but is most admirably treated. As would be 
expected, there are many species common to Lake Michigan and 
the Lake of the Woods. The sand hills in the interior have 
been studied by Rydberg, Hitchcock, and Pound and Clements. 
Hill has studied the dune floras about Lake Michigan for many 
years, and although he has not written a great deal along ¢c0 
logical lines, he has had the ecological standpoint thoroughly i 
mind and the author has received from him a number of valuable 
suggestions. 
THE UNIVERSITY OF CHICAGO. 
BIBLIOGRAPHY. 
BOERGESEN, F.: Beretning om et Par Exkursioner i Sydspanien. 
21: 139. 1897. 
BOERGESEN, F., and PAULSEN, O.: Om Vegetationen pa 
diske Oer. Copenhagen. 1898. 
Borss, V.: Die Vegetation der ungarischen Sandpuszten 
die Bindung des Sandes. Abstract in Bot. Cent. 19: 92. ! 84. 
Bot. Tid. 
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