227 



1. An alga growing under steady normal conditions con- 

 tinues, in the region studied, to grow in a healthy vegetative 

 state throughout the year. 



2. A sudden change in external conditions checks the vegeta- 

 tive growth of an alga and tends to cause it to enter a resting 

 stage or to form fruit sexually. 



3. Spirogyra varians is the most widely distributed alga found 

 in this region. It grows under varied conditions. It conjugates 

 at all seasons of the year, depending on hard external conditions, 

 e. g., the drying up of the pond. 



The Bureau of Plant Industry has recently given to Science 

 authoritative statements regarding the nature of its seed and 

 plant distribution. Among the beneficial activities thus described 

 are the introduction of rapidly growing Arabian alfalfa, which at 

 Mecca, California, last year yielded twelve cuttings instead of 

 eight ; the distribution of two new timothies, one of which ripens 

 with red clover, the other being a large yielder ; the successful 

 introduction of the date in California and Arizona ; the distribu- 

 tion of improved melon, cotton, and tobacco seeds ; the introduc- 

 tion of thousands of Japanese rush and sedge plants for the 

 matting industry ; * and the department is at present importing 

 hard bamboos from China, drought-resistant forms from India, 

 and giant forms from Porto Rico. 



An article on " Plant Pathology in its Relation to Other Sci- 

 ences," by Dr. Ernest Shaw Reynolds in Science for June 19, con- 

 tains the following : " We must know the normal functions of the 

 plant attacked, and be able to realize in what: way they have been 

 deranged. Thus, if a parasite is the cause of the disease, it may 

 bring about the death of the host-plant in one or more of the fol- 

 lowing ways : It may strangle the plant by clogging the water- 

 conducting vessels, as in the bacterial "wilt" of melons, already 

 referred to. Again, it may give out a poison which kills the pro- 



* Editor's Note. — The New York Tribune for September 16 announces that in 

 Saskatchewan " hundreds of square miles of reeds available formatting" have been 

 discovered ; the credit is apparently due to the United States government. 



