692 Journal of Agriculture. [10 Nov., 19 10. 



stuck in adhering mud or soil. If a farmer has a good paddock free 

 from Onion Grass, it would be worth his while, when placing stock in 

 it at that time of the year, to see that they do not walk across ground 

 where Onion Grass is abundant before entering the field, or if that cannot 

 be avoided, to make them walk through water to clean their feet. If 

 a patch of Onion Grass appears in a paddock, its further spread may 

 often be pre\-ented by fencing it off for a time and merely loosening and 

 manuring the .soil on and around the patch. Dozens of similar instances 

 could be given w'hereby the exercise of foresight and by trifling immediate 

 exertion great future trouble could be avoided. 



The influence of animals on the spread of weeds is not of course con- 

 fined to stock. Mistletoe, for instance, is carried by small birds. Many 

 small weeds are carried by ants from place to place and other instances 

 could be given. A curious instance of the action of fowls in favouring 

 the survival of weeds may be mentioned. A particular plot of ground, 

 overrun by a few fowls, contained mainly Rye Grass, Dutch Clover and 

 Prairie Grass with small amounts of Couch Grass, Plantain, Dock, and 

 Burr Clo\er. Although the ground was too hard to scratch or break in 

 summer, and the turf too thick in winter, within one year both the clovers 

 and the two first-mentioned gras.ses had practically disappeared leaving 

 mainly Plantain with a little Dock and Couch Grass. Hence, although 

 fowls may destroy insects in a pasture, their general action will be to cause 

 it to deteriorate, particularly if allowed on it in spring when young grass 

 and clcn-er seedlings are endeavouring to establish themselves. 



The origin and incidence of the diseases of animals and particularly 

 those of man, have been more closely studied and more fully investigated 

 than the diseases of plants have been as yet, but it is not so long ago that 

 very vague and, in part, erroneous ideas were prevalent as to the spread 

 and transmission of such common animal diseases as consumption and 

 typhoid fever, for instance. To some extent, this lack of knowledge 

 is compensated by the greater facility with which many plant diseases 

 could be attacked or even extirpated, if a tenth of the attention devoted 

 to the diseases of man and other animals were paid to them. It is not, 

 for instance, possible to collect all patients showing signs of consumption 

 and subject them to cremation, but this can be done in the case of diseased 

 plants and usually at less cost than when, for instance, the destruction of 

 stock animals is rendered necessarv by the spread of swine fever or 

 anthrax. In very many cases, simple and effective means of treating 

 plant disea.ses are already known, which do not involve the destruction 

 of the diseased plant or part, and which are comparatively inexpensive. 

 There are, of course, certain obscure di.seases of plants such as bitter pit 

 in apples, certain cancerous growths in trees and many other little known 

 diseases of cultivated plants, of which little is known and for which no 

 effective cure or remedy has as yet been found. This is, however, 

 hardly surprising when we consider that Plant Pathology is one of the 

 youngest of the sciences and that as yet ^•ery little work has been done 

 in this direction on an experimental, scientific basis. There are few 

 departments of human knowledge which offer as great opportunities for 

 scienitific research and in which the economic value of the results obtained 

 is likelv to be .so great. 



It is, for instance, within the lifetime of an individual that the cause, 

 spread and modes of treating many of the most injurious rust and smut 

 fungi have been exactly determined, that the existence of bacterial diseases 



