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object being, of course, to observe the subsequent effect on the leaves. 

 The commonest of the thrips found on roses was the form principally 

 experimented upon, and the following is an account of the operations 

 and their results. 



On 5th October several dozen thrips were taken from roses and 

 transferred to the unfolding bud at the end of an apricot shoot. 

 I found it the best way to shake the rose over a smooth surface, 

 and then to pick up the insects with a No. 1 sable brush, keeping the 

 brush constantly wet with water or saliva, the latter having just the 

 right degree of adhesiveness to prevent the thrips from springing off. 

 The transfer has to be quickly made or the insects escape by throw- 

 ing themselves loose from the brush. At first I used a magnifying 

 glass, but soon discarded it. The insects were " fenced " in with a 

 ring of cotton-wool tied round the apricot shoot. The shoots must be 

 handled with the utmost care to avoid injury. They are very sensitive. 

 The older insects displayed a tendency to wander about, and ultimately 

 many of these got lost in the cotton wool or flew away. The younger 

 ones soon ensconced themselves amongst the youngest leaves of the 

 bud that were sufficiently spread to allow of their entrance, and they 

 remained in that position. From time to time I looked at the bud 

 with a magnifier, and satisfied myself that they were still there and 

 alive, and to all appearances, well and happy. Whether they tried 

 to feed I could not see. Twenty-four hours later they were all right. 

 Accordingly, another bud was infested in a similar manner. A third 

 hud was infested from the flowers of the white snapdragon. White's 

 universal movement clamp was serviceable in this work, as it enabled 

 me to place an 8 x 10 plate of glass in a horizontal position near 

 whatever bud was to be infested, so that the insects could be shaken 

 out on to a smooth clean surface, whence they could be easily and 

 quickly transferred to their new quarters. 



Forty-eight hours afterwards all these insects appeared to have left 

 the buds, though it was impossible to be sure of this, as some might 

 be hidden among the recesses of the bud. It would seem that some 

 of them died, as I found one dead body. Starvation or poison might 

 account for this ; there would be nothing surprising in such a result, 

 considering the differences between roses and apricot buds, and 

 especially the presence in the latter of a larger proportion of cyanogen 

 compounds. The single death noted proves nothing, however, as 

 it is quite possible that some of the insects were injured during the 

 transfer. There were dark remains as of excrement in both the 

 transfers from roses. 



On 10th October one of these apricot buds had at least one small 

 light-coloured thrips in it, possibly one that had been overlooked in 

 the previous examination on the 7th. Or it might possibly have 

 hatched out since that date. 



The leaves from the buds handled in this manner did not do well. 

 They did not grow to full size, and they were not well formed. They 

 did not develop shot-holes. If any conclusion can be drawn from the 

 experiment it is that the common rose thrips refuses to inhabit the 

 apricot bud. 



