H. WOKMALD AND L. K. WoRMALD 205 



In conclusion, we should like to thank Dr Eyre, who indicated the 

 possibility of preparing an emulsion by the method adopted,, and at 

 whose suggestion the above experiments were carried out. 



DESCRIPTION OF PLATE XI 



Photograph of potato shoot described on p. 201 . The two healthy leaves seen on the 

 right had been sprayed with copper emulsion and then inoculated with zoospores of Phy- 

 tophthora infestans; the diseased leaf occurring between these had been Ic^ft unsprayed and 

 had been inoculated. The remaining leaves on the shoot had become naturally infected. 



Ami. Biol. V 14 



