MISCELLANEOUS NOTES 275 



application is necessary, and he will have to continue the 

 operation for many days or weeks in succession. In such 

 a case it cannot be said that the operator knows " how to 

 spray." He does not ; and from the beginning he has, for 

 want of experience, been doing work which is of a useless 

 kind, although not utterly so, because he has actually 

 killed a certain (small) number of fungus spores ; but how 

 much better would the work have been performed had he 

 collected the pod and had it destroyed by one of the 

 several methods recently suggested ? If the operator is 

 asked to spray " canker " he will proceed probably by the 

 stereotyped process which has been commonly laid down, 

 viz., to cut out all the cankered area, spraying it before, 

 after and during cutting, and then treat the wounds with 

 the barbarous " Salamander," or heated iron of Ceylon, 

 and with antiseptic dressings. 



Now no one, not even the most expert mycologist, can 

 tell in the field when all the cankered area has been cut 

 away, especially if treating Nectria Theobromce or stem 

 canker, or canker induced by the Black Rot fungus, and 

 therefore the spraying given has done little more than 

 reduce the number of spores, thus preventing in a small 

 measure only the spread of disease, neither has the 

 " Salamander," or antiseptic, had any better effect. It 

 can, however, be ascertained in the laboratory whether the 

 cuts have been made beyond the disease area, and also 

 whether all infected material is removed, if sections of the 

 parts are microscopically examined, but byno other method. 

 Here again the planter meets a difficulty ; he cannot get 

 every canker spot examined under the microscope, for 

 that would be impracticable with the many thousands 

 to be attended to. This points out the fact that spraying 

 cankers is only partially effective, and only serves for the 

 destruction of the exuded spores, for the spray cannot be 

 made to enter and distribute itself through the cells of the 

 wood and destroy the growing mycelium existing there. 



There is another factor to be taken into account in 

 connection with the application of sprays used for different 



