22 



amounts for smaller trees were taken as proportionate to the pro- 

 ducts obtained by multiplying the heights of the trees by their 

 diameters. The amounts for larger trees were calculated in a 

 different manner, seemingly by increasing the amount by one ounce 

 (60 per cent, cyanide) for each two feet additional in height and 

 diameter, or by one-half ounce when the addition was two feet in one 

 direction only. The difference of one ounce with each two feet was 

 probably observed in the computation of the amounts for the smaller 

 trees and taken to be a constant difference with this difference of 

 size. There is no doubt about the absurdity of the table, whether 

 this be the correct explanation of its computation or not. The table 

 published by Mr. D. W. Coquillett at an earlier date is based upon 

 the use of proportionate amounts for trees of different sizes, as is the 

 table given here. 



PURPLE SCALE, Mytllaspis citricola, Pack. 1, infested leaf ; 2, female scale from 

 above ; 3, same from beneath ; 4, male scale ; 1 is natural size and the others are 

 much enlarged. (From U.S.A. Dept. Agr.) 



Known in two orchards in the colony. This is a very injurious scale in the 

 South of Europe and in Florida. 



