University of Arizona 



Agricultural Experiment Station 



Bulletin No. 79 



Plant of Opuntia /icw tnrfj'ca in the introduction garden, University Farm, badly injured 

 with a temperature of 21 degrees F. The illustration shows 6 months growth since the freeze. 



Cold-Resistance in Spineless Cacti 



By J. C. Th. Uphof 



INTRODUCTION 

 By J. J. Thornber 



Tucson, Arizona, December 1, 1916 



