82 PLUM. 



white arsenic, is on account of its injurious effect on foliage, it being 

 soluble in water and acid in its character. 



" The arsenic set free in the soap solution is neutralized by the free 

 alkali of the soap, so that where soap solution can be used per se 

 without harm, no injurious results from soluble arsenic need be appre- 

 hended when to it is added Paris-green in the right proportions. 



" In all the above experiments the soap solution was at the 

 ordinary temperature of the atmosphere when added to the Paris - 

 green. If heat had been used undoubtedly a larger portion of arsenic 

 would have gone into solution." — Frank T. Shutt, M.A., F.I.C., 

 F.C.S., Chemist, Dom. Expl. Farms. 



PLUM. 



Plum Sawfly. (For scientific names, see note, p. 84.) 



During the past season, I received from a few different localities 

 specimens of young Plums infested by Sawfly grubs, which were 

 obviously doing much mischief by clearing out the young kernel, and 

 sometimes further injuring the centre of the fruit, and consequently 

 causing it to fall very prematurely. 



On the 22nd of June, I received a communication from the Rev. 

 Henry H. Slater (Urchester Vicarage, Wellingborough), mentioning 

 that his Plums were heavily attacked by a grub which he was not able 

 to identify, and he therefore forwarded a few of the fruit for exa- 

 mination. He remarked : — " It appears to me that the attack has 

 been made and the eggs introduced very shortly after flowering, 

 because, when the puncture occurs at the extreme end of the fruit, the 

 exuding gum has often fixed the remains of the flower. I should say 

 that the creature lias injured quite half the crop." 



The injured Plums varied in size from about, or a little over, half- 

 inch to an inch in length. In somewhere about nineteen examined, 

 I found the fruit usually to have one boring near the end opposite to 

 the insertion of the stem. In a few cases there were two injured 

 spots ; the tunnels were sometimes open, sometimes choked with black 

 gummy znaterial. 



On opening the fruit I fouad the kernel gone, and often some 

 amount of marks of gnawing round the cavity where the kernel had 

 lain ; this cavity being more or less filled with blackish decayed 

 matter. 



