7O BOTANICAL GAZETTE [JANUARY 
throw light upon the questions of what crop plants make most economical use 
of water and of what wild plants are best suited to their desert and semi- 
desert habitats. A former review* has called attention to the investigation of 
these problems by SHANTz and Briccs during 1910 and 1911, while a more 
recent paper reports the results of the same investigators*’ obtained during 
the summers of 1912 and 1913. The investigations are remarkable for the 
extensive scale upon which they have been conducted, and for their duration 
throughout the growing season. More than 50 species have been the subjects 
of study, and for some the period of investigation extends over three years 
and includes many individual plants grown from seedling to maturity, the 
final result being the average of many determinations. As a rule, the same 
variety gave consistent results, although considerable differences were found 
between different varieties of the same plant; for example, the variety of 
alfalfa having the highest water requirement was nearly 50 per cent above 
the lowest. 
Millet has proved throughout an excellent dry land crop, producing a 
unit of dry weight for every 310 units of water absorbed. It is closely followed 
by sorghum with a water requirement of 322, corn with 368, and sugar beet 
with 397; then come wheat with 513, barley with 534, oats with 597, alfalfa 
with - and others that it is impossible to enumerate here. Weeds show 
the greatest known range from such economic forms, as Amaranthus with 292, 
Soleo yoineige with 336, Bouteloua gracilis with 389, through such intermediate 
s Xanthium commune with 432, Grindelia squarrosa with 608, an 
Helianthus petiolaris with 683, up to Ambrosia artemisiaefolia with 948 and 
gropyron Smithii with 1076. Like previous investigations by the same 
workers, this report contains a vast amount of exact quantitative data of value 
in studying the agricultural possibilities and the ecology of the great plains.— 
Gro. D. FULLER. 
The origin and relationships of the Indonesian flora.—It is well known 
that WALLACE, basing his conclusions chiefly on animals, held to the idea of a 
sharp boundary line in the Straits of Macassar, separating the Indo-Malay 
and Australasian biogeographic regions. Not only were Borneo and Celebes 
thus separated biogeographically, but the line was supposed to separate such 
closely adjoining islands as Bali and Lombok, east of Java. Botanists gener- 
ally have not found sharp lines between the Malay and Australian floras. 
HALLIER,* working under excellent auspices, finds that Asiatic types extend 
4 Bot. Gaz. §6:514-515. 1913. 
5 Briccs, L. J., and SHantz, H. L., Relative water requirement of plants. Jour- 
Agric. Research 3:1-63. pls. 7. 1914. 
* HaLtier, Hans, Die Zusammensetzung und Herkunft der Pflanzendecke 
Indonesiens. Separate reprint from J. ELBert’s Die Sunda-Expedition des Vereins 
fiir Geographie und Statistik zu Frankfurt am Main 2:275-302. figs. 2. 1912- 
