CONTENTS xvii 



CHAPTER XX 



INSECTS ......... IQb 



Mussel Scale 



Description of the insect ; its enemies ; damage done by it ; 

 character of investigation of insecticides ; effect of alkalis, 

 alone and with paraffin, soap, alcohol, etc. ; effect of paraffin ; 

 of different soaps; winter washing on different dates; effect 

 of other insecticides ; lime and lime-sulphur washes ; fumiga- 

 tion; check experiments by counting the hatchings; glueing 

 of the scales to the bark by alkalis ; summer treatment ; effect 

 of rain after spraying ; nature of the action of the insecticides. 



CHAPTER XXI 

 INSECTS (continued) . * . .'..' ... 212 



Currant Gall Mite 



Life-history ; treatment with paraffin, carbolic acid, etc. ; 

 possible infestation of the ground ; cutting down infested 

 bushes ; fumigation ; treatment with hot water ;. susceptibility 

 of different varieties. 



CHAPTER XXII 



INSECTS (continued) . .* . . . ; . * . 219 

 (i) Woolly aphis; spraying with paraffin; fumigation of young 

 trees ; dipping in hot paraffin or hot water. (2) Apple sucker ; 

 damage done by it ; winter treatment with various insecticides ; 

 spring treatment ; lime-salt washes ; nicotine. (3) Aphis ; 

 treatment with weak emulsions and with nicotine. (4) Cater- 

 pillars ; treatment with various poisons ; efficacy of lead 

 arsenate and paraffin emulsions ; importance of winter washing. 



CHAPTER XXIII 



FUNGI ... . . .. . . .- . 231 



Silver Leaf Disease 



Nature of the disease ; plants attacked by it ; recent spread of 

 it; attacks dependent on inoculation; inoculation in stem, 

 roots, or branches ; inoculation at different times ; recovery 

 from attacks ; susceptibility of different kinds of trees ; of 

 different varieties of plums ; of strong and weak trees ; possible 

 immunisation from attack; treatment with iron sulphate; 

 preventive measures; disease communicated solely by spores. 



CHAPTER XXIV 



FUNGI (continued) . . . . . . 241 



Potato Disease 



Treatment with copper fungicides ; average benefit ensuing ; 

 measurement of results ; fallacy of drawing conclusions from 

 the state of the haulms ; possible deleterious effect of spraying ; 

 effect of spraying influenced by the manurial treatment; 

 general view of the problems involved; steeping the seed 

 potatoes ; cutting down diseased haulms. 



