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idea, for the least injury was carefully prevented, so 



that contact with the sap was avoided; on the other 



hand contact was produced when searching for caterpillars. 



The following experiments were made: 



On March 9 th 1903, forty seedlings were set out on a 



perfect homogeneous plot of land on four places adjoining 



one another, four rows of ten plants each. By doing 



this four small plots were obtained, viz. A, B, C and D. 



In Plot A and D one calico seedling was intentionally 



set out, viz. in plant hole n° 1 in both cases; ail the 



remaining plants in each plot were perfectly healthy. 



Each morning caterpillars were searched for in thèse 

 plots, this being carried out in a spécial way. 



Plot B and C had always the first turn and there ail 

 the plants from number 1 — 40 were searched one after 

 the other. 



After that the even numbers (plants 2, 4, 6 etc— 40) 

 were searched firstly in Plot D, which being done, ca- 

 terpillars were looked for on the uneven numbers (plants 

 1, 3, 5 etc— 39) beginning with plant number 1. 



Lastly it was the turn of Plot A where beginning 

 with plant number 1, ail forty plants were examined 

 one after the other. 



The resuit was as follows. 



Plot A: Ail plants except one showed already at the 

 second banking, viz. twenty-four days after 

 setting ont, the symptoms of the disease; 

 only plant number 22 persisted in remaining 

 healthy during forty -nine days but then it 

 also became diseased. 

 Plot B: Ail plants remained healthy except plants 

 number 4 and 7 which both showed the 

 symptoms of the disease in the top though 

 only at the last. 



