THE 



RADIO-ATMOMETER 



Is a black-brown form of the white Atmometer, aheady 

 widely known. The manner in which it may be used 

 in conjunction with the white Atmometer in studies of 

 light intensity has been described by the devisor, Prof. 

 B. E. Livingston, in the following papers: 



The Plant Worlds vol. 14, pp. 96-99, May, 191 1. 



The Botanical Gazette, vol. 52, pp. 418-438, December, 1911. 



These black-brown cups can now be supplied in the natural 

 state at $1.00 each; $8.00 per 10. 



THE PLANT WORLD 



TUCSON ARIZONA 



THE F. RONSTADT CO. 



TUCSON - = ARIZONA 



AGENTS FOR 



PLANET JR. GARDEN TOOLS, IMPLEMENTS, PUMPS 

 ENGINES AND WINDMILLS 



OLYMPIC NATURE NURSERY 



THE FOREST CONSERVATORY 



WILD FRUITS, PLANTS AND FLOWERS 



Oregon Grapes, Blueberries, Blackberries, Raspberries, Salalberries, 

 Salmonberries, Rhododendrons, Spireas, Trilliums, Ferns, 

 Evergreens, Maples and other Native Plants 



Collected from the forest for sale or exchange. Catalogue mailed on request 

 JOEL SHOMAKER, Nellita, Washington 



