Fig. 61.— 0. (liUciiii whose sickly appearance is due to tlie " Zone Spot Disease." Antigua. 



Fig. 62.— 0. dillenii showing con; 



siderable destruction of its segments as a result of the " Zone 

 Spot D'isease." Antigua. 



1 ,- .T nfv; snecies. Thousli growing beside plants of 

 Fig. 63.-An Opuntia winch Dr. N.Bvtton regards as -\; l- ^^^^^,,^^, \,r..^e.i.A by ,t. Ant,gua. 

 0. dilknU attacked by the "Zone Spot (Figs. 61, 6,), this sixc 



