BUREAU OF PLANT INDUSTRY. 295 



ran^e of differences, such as bearded or beardless beads, very open 

 or closely crowded spikelets, white, red. or black chaff, with smooth, 

 prninose, or velvety surfaces, dark or light grains, etc. The occur- 

 rence of this primitive diversity under conditions that admit of 

 normal cross-fertilization indicates that the same method of accli- 

 matization can be applied to wheat as to diverse types of cotton or 

 other cross-fertilized crop plants. The full range of adaptation of a 

 widely diversified type can be obtained instead of the limited possi- 

 bilities of a self- fertilized strain that may have been selected because 

 of its adaptation to entirely different conditions. The possibility of 

 acclimatizing new types of wheat adapted to arid subtropical dis- 

 tricts of the Southwestern States becomes worthy of careful investi- 

 gation. 



Acclimatization or tropical crops and ornamental trees. — 

 Conditions are now favorable for a thorough test of the possibilities 

 of acclimatizing tropical crop plants, rubber-producing trees, and 

 ornamentals in the warmer districts of Texas, Arizona, and Cali- 

 fornia. The numerous towns and villages recently established afford 

 sheltered situations, and the people are anxious to undertake experi- 

 mental plantings and give them the necessary care. The protection of 

 an irrigating canal or a warm spring sometimes proves sufficient to 

 permit the growing of avocados or other tropical trees, even in locali- 

 ties otherwise subject to severe frosts. 



Cultural possibilities of the coconut palm. — A study of the 

 botany, history, and biology of the coconut palm shows that this 

 most useful tree is not limited to tropical maritime conditions. 

 Though generally cultivated on seacoasts, it is able to thrive in in- 

 terior localities with sufficient heat and sunlight. Hardier varieties 

 that may prove capable of acclimatization in the United States are 

 to be sought in the original home of the species in the interior of 

 South America. Experiments should not be confined to the coast of 

 southern Florida, but extended to frost-free interior localities in the 

 Southwestern States. 



DRUG-PLANT, POISONOUS-PLANT. AND GENERAL PHYSIOLOGICAL 



INVESTIGATIONS. 



The work of the Bureau on drug plants, poisonous plants, and other 

 special physiological problems has been continued along the lines 

 described in previous reports, under the immediate charge of Dr. 

 Rodney H. True, Physiologist. 



WORK ON DRUG PLANTS AND OTHER SPECIAL CROPS. 



The field work, largely carried on at the several testing gardens, 

 has covered a large number of sorts of plants, both imported and 

 native. Through tlie effective cooperation of the Office of Foreign 

 Seed and Phint Introduction, plants from various parts of the world 

 have been received and placed for trial in such of the testing gardens 

 as promise to yield the best results. 



Drug-plant testing oardkns. — The garden located on the experi- 

 mental farm at Arlington, Va., under the care of Dr. G. F. Klugh, 

 Scientific Assistant, continued to receive a large part of the plants 



