Island marshes was carried out with the co-operation of the Ontario Department 

 of Health, and tularemia was diagnosed as the cause. A considerable amount of 

 time was spent in collecting information on the occurrence of rabies in wildlife 

 in Ontario in co-operation with the Canadian Department of Agriculture. Re- 

 ports on the disease and its status in Ontario were prepared for the information 

 of the Departmental staff. 



Studies of Wolves in Ontario 



The investigation of the taxonomy and distribution of the brush wolf in 

 Ontario was continued. A large series of skulls borrowed from museums in 

 Canada and the United States were examined and diagnostic measurements from 

 each were recorded. The stock of breeding brush wolves and brush wolf x dog 

 hybrids kept at the Midhurst Forest Nursery was increased by two litters re- 

 sulting from brother x sister matings in F2 hybrids. Six matings between F2 

 hybrids and brush wolves were made, three of which were successful. Six 

 F2 hybrids from previous matings were sacrificed and preserved for comparative 

 study. 



A study of methods of aging brush wolves and timber wolves was in- 

 itiated. Preliminary examination of the teeth indicates that the pattern of re- 

 placement and ex^'^Uation may be useful in aging these species. 



Control of Meadow Mice in Reforestation Plantations 

 During the summer of 1955, a preliminary study of field mice in re- 

 forestation plantations was carried out. The main objectives were to develop 

 a simple and rapid method for assessing populations and to test zinc phosphide 

 as a poison. Results so far show that more work is required before any adequate 

 method of assessing populations will be available. Zinc phosphide in our ex- 

 perience and that of others appears to be a satisfactory poison which should be 

 more generally used on an operational basis. 



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