APPOINTMENT OF COMMISSION. 



Department of Public Lands, 



Brisbane, 10th September, 1912. 



To Messrs. Thomas Harvey Johnston, M.A., D. Sc, F.B.S., and Henry Tryon. 



Gentlemen, — I am dirdfcted to inform you that the Governor in Council has been pleased 

 to appoint you to be a Commission of Inquiry to visit countries in which prickly-pear plants are 

 indigenous, or have become naturalised, for the purpose of ascertaining if there are present in 

 such countries any natural enemies of the prickly-pear that may be utilised for the destruction 

 of the plant in Queensland, and also of inquiring into the possibiUty of utihsing prickly-pear for 

 commercial purposes, and has also appointed Thomas Harvey Johnston to be Chairman of the 

 Commission. 



Li conveying to you this decision I am desired to state that the Government wish you to 

 give consideration to the following points (among others that may suggest themselves to you) 

 with respect to the various species of prickly-pear and alUed Cactacese, viz. : — 



1. What diseases parasitic plant organisms and parasitic or predatory insects are injuriously 

 related to these plants, and the nature, character, and extent, in each case, of the injuries. 



2. The circumstances of the occurrence of all such agents affecting these plants. 



3. The checks, if any, that control or impair the exerpise of the full virulence of all such 

 agencies, and the nature of such checks. 



4. The iatroduction into Queensland, subject to the ehmiaation of any such checks, of 

 such diseases, parasitic plant organisms and parasitic or predatory insects, and their estabhshment 

 therein in connection with the naturahsed species of prickly-pear already growing at large within 

 the State, having regard to the question of destroyiag, subjugating, or controlling them without 

 ill effect on any object whatever other than prickly-pear. 



5. The possibility of utihsing prickly-pear for commercial purposes, and so destroying it by 

 means of its utilisation. 



I have the honour to be, 

 Gtentlemen, 

 Your Obedient Servant, 



P. W. SHANNON, 



Under Secretary. 



