12 



used in Europe to keep down mosquitoes. In favorable condi- 

 tions, it grows so densely as to cover the water with a mat that 

 keeps out light and air, thus restricting the development of 

 mosquito larvae. In the Queens locality it was not as dense as 

 this, merely scattered plants, a few to the square inch, floating 

 among the much denser Lemna. Since pending plans for fur- 

 ther park development are likely to obliterate this kettle hole 

 altogether, perhaps some of this Azolla could be transplanted 

 into some pond or still stream where it would be permanently 

 safe. It ought to do well in water gardens, and would make an 

 unusual species and give an attractive color growing in masses. 



Queens — Long Island, N. Y. 



