44 



After I had become fairly well satisfied that certain very small 

 insects, working in the opening bud, were instrumental in causing 

 shot-holes, I _ began a series of observations on such buds and their 

 unfolding leaves. An account of some of these observations will now 

 be presented. 



Notes on successive sizes and conditions of Apricot Shot-holes on mature 

 leaves, March-April, 1901. 



It was concluded that at that season of the year (March 9 to April 27) this particular 

 series of shot-holes were in a stationary condition. 



Notes on successive sizes and conditions of Apricot Shot-holes on very- 

 young leaves, October-November, 1902. 



No. 1. This leaf measured 36 x 18 millimetres on October 24th, and at that time bore 

 two " shot-holes" and a mechanical injury of another kind. Before the second measure- 

 ment a storm had interfered and one of the two original holes had been torn off with the 

 portion of the leaf in which it had been located. 



Another leaf on the same branch contained three holes, '6, 1", and 1 "5 millimetres long, 

 and these became larger in the course of ten days, as is indicated by the following 

 measurements given in the same order as above : T4 x 8', 3'7 x 2', and 5'4 x 2. The 

 amount of increase shown by the figures 1 "4 x 8, is deceptive, inasmuch as the great 

 increase in length is due to the addition of two adjacent spots. The branch was broken 

 by accident on the tenth day. 



No. 2. This leaf was 19 x 10 millimetres at the beginning of the experiment, and had 

 attained at the close of the experiment the dimensions 88 x 75 millimetres. Whenever 

 examined the branch on which it grew was found to be free from aphides and ants, but 

 some Thrips insects were seen. At the outset there was a single hole, and upwards of 



