33 



manner in wliicli these instrnetions wei-e cari-ied out, the time and 

 hibor involved in the work, and tlie value of Mr. (-ary's observations 

 will be indieated by his I'eport. 



Ml". Car}^ commenced these experiments May 2'.»; his i'ei)ort Avas 

 submitted ()etol>er r, and 10, IDOO. It is as follows: 



Camp in the Meadows. Maine, 



October 6, 1900. 

 Dear Professor Hopkins: I send you herewith report of iny observations this 

 season. They do not go very far toward solving the problems suggested, but as 

 to Dendroctonus it seems to me they do teach considerable. 



Sincerely, vours. Austin Gary. 



All of the trees girdled are of Red Spruce, and unless otherwise mentioned were 

 to all appearances healthy. 



The inferences to be drawn from the results de])end considerably on surround- 

 ings, the lay of the land, and the relation of the girdled trees to infested and 

 healthy ones. 1 will therefore g.oup my notes according to localitits. 



CtROUP 1. 



Group I is at edge of Wights cutting of winter of 1899-li)0U and near the clump 

 of infe-ted tiees examined on May ~'8 by yourself and the writer. Unless other- 

 wise stated, the trees were hack-girdled b.y stii'ving an ax through the bark and 

 into the sapwood around the trunk :! to ") feet above the base. 



Ti-ees girdled on Mat/ 39. 



Tree No. 2: Diameter 28 inches: examined June 19, July 9, September 1. and 

 October 4: not attacked by Dendroctonus.' A few Xyloterus - entered the wood 

 in the girdle. 



Tree l>]o. ;J: Diameter 13 inches; girdled by A. D. H. ; examined on June 19, 

 July 9, and September 1: not attacked by Dendroctonus. ()ctober 4. seemed to be 

 losing leaves: sapwood' at girdle and for a foot above stained bluish one-half inch 

 deej). 



Trees girdled June 19. 



Tree No. 24: Diameter l.'i inches. July 10, attacked by a few Xyloterus. Octo- 

 ber 4, no change. 



Tree No. 2.5: Diameter 18 inches. July 10. numerous Xyloterus entering at and 

 near girdle. October 1. no change. 



These four trees are about 30 yards from infested trees and about 75 yards from 

 the clump of trees first examined on May 28. 



Tree No. 26: Diameter 20 inches; 30 yards from clump of infested trees. July 

 9, a few Xyloterus entering wood at girdle- bark infested with Dendroctonus, 

 Polygraphus ■ especially abundant below the girdle; a few Sierns anuectens found 

 below girdle. September 1, Dendroctonus larv;e were observed. October 4, 

 recently developed beetles and a few Tetropium larv;ie occurred in the bark, with 

 numerous Xyloterus in the wood: the bark was then loose, the leaves down, and 

 the wood turning brown. 



Tree No. 27: Diameter, i.") inches: 40 feet from infested trees. July 9, infested 

 by Dendroctonus and Xyloterus in girdle; Dendroctonus galler.es up to 3 inches 

 long, with numerous eggs. September 1, numerous larvae and pup* of Dendroc- 



' Dendroctonus j^iceaperda Hopk. ' PohjgrapliUH riiftpennis, Kirby-Hopkins. 

 ■-' Xyloterus bivitfatus Kirby. 



3506— No. 28— Ul .-J 



