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economic plants, shrubs and trees and, on the other, with plant 

 pathology which concerns the diseases which attack vegetation. 



In the former section the Dominion Botanist gives careful 

 study to newly introduced weeds and others that by reason of serious 

 prevalence or persistent habits threaten the crop production of a 

 vicinity. Besides communicating helpful information to corres- 

 pondents who send specimens, or report the presence in their crops, 

 of special weeds, occasion is taken to warn farmers in certain districts, 

 threatened by the invasion of weeds, which may result in serious 

 consequences. To this end posters of warning showing specimens 

 in natural colours are widely distributed in sections likely to be in- 

 jured. 



This Division co-operates with the Health of Animals Branch in 

 identifying and suppressing plants that by reason of their poisonous 

 properties endanger the health of farm animals. Study is given 

 also to plants that may possess economic properties for manufacturing, 

 medicinal or other commercial purposes. 



In the work of plant pathology this Division exercises a far 

 reaching benefit in the study of plant diseases. Study is given to 

 diseases of cereal, fruit and vegetable crops as well as of forest trees. 

 A constant vigilance is maintained in order to prevent the intro- 

 duction of diseases new to the country. In cases of dangerous 

 introductions these are dealt with by regulations made under the 

 Destructive Insect and Pest Act to prevent the importation or 

 distribution of infected vegetable matter. Besides this all reasonable 

 means are taken to warn the public of possible danger from threat- 

 ening plant maladies. Plant diseases are studied partly in the 

 pathological laboratory and partly in the field and pathological 

 greenhouse. Amongst the diseases at present under investigation 

 may be mentioned silver leaf of fruit trees, scab and rhizoctonia 

 disease of potatoes, smut diseases of grains and several others. 



The spacious and richly planted botanic gardens and arboretum 

 of the Central Farm have been placed in charge of the Dominion 

 Botanist. Their scenic beauty and situation well serve as a centre 

 for botanical study. Together with a well classified large herbarium 

 of the Flora of Canada exceptional opportunities are thus placed 

 at the disposal of the scientific student and interested public. 



