INTRODUCTION. 21 



cessful measures must be general. Each cultivator ought to be able 

 to work in full knowledge of the cause ; he ought to be able to obtain 

 information on the nature of the diseases which he observes, and the 

 means which should be used to combat them. All interested should 

 be able to act simultaneously over a large extent of territory, a con- 

 dition which will alone crown any individual effort with success. 

 There now exist in certain agricultural centres laboratories where all 

 questions are solved gratuitously. These institutions are intended to 

 help cultivators, and to supply them with the means of combating the 

 diseases which ravage or menace their crops. The movement in 

 favour of these institutions where all phytopathologic questions are 

 studied, and which centralize all the observations made by interested 

 parties on the diseases, the presence of which they have observed, is 

 especially accentuated in Germany. When the prosperity of a country 

 is threatened by the appearance of a disease and by its generalization 

 it is necessary to take general measures. These are made imperative in 

 many cases on cultivators by arretes [an arrete is possibly equivalent 

 to our Order in Council]. 



If one considers that the damages caused annually to French 

 crops by injurious insects, according to the calculations of authorized 

 persons, amount to several hundreds of millions (a million francs = 

 £40,000), that the loss due to cryptogamic disease reaches a still 

 higher figure, an idea can be gained of the great necessity there is to 

 generalize the methods of struggling against parasites, and the neces- 

 sity of simultaneous action by all under the control and the direction 

 of official agents. The first order dealing with the protection of 

 crops against injurious insects is that of the Parliament of Paris of 

 date 4 February, 1732 ; then came the Act of the 26th Ventose Year IV, 

 which rendered obligatory the destruction of grubs in general (modi- 

 fied by the Act of 24 December, 1888). It especially prescribes the 

 destruction of the grubs of Liparis chrysorrhea, the brown-tailed moth, 

 the agglomerations of which in winter and in spring form silky 

 wrappers between the branches of fruit trees. The Order declares that 

 " After the date fixed by the Prefect, farmers who have not submitted 

 to the prefectoral order, will be liable to a fine of six to fifteen francs, 

 and obliged to pay to the administration the expenses incurred by it 

 in grubbing on their domains ". The panic created by the appearance 

 of the phjdloxera in 1863 was followed by an effect which has made 

 itself felt in all branches of cultivation. Examination Commissions 

 were fox'med, a National Agronomical Institute was founded in Paris. 

 Chairs of Agriculture were created, new laws were passed, the Ad- 

 ministration is working with equal solicitude at all cultural pests, 

 and it has enacted the measures required to cope against the ex- 

 tension of diseases. As a consequence of the International Phyl- 

 loxeric Convention held at Berne, an order of 10 September, 1884, 

 interdicted the exportation and importation of rooted-up stocks and 

 of sprouts (shoots). Then the destruction of insectivorous birds has 

 been forbidden. Cultivators too often misconstrue their precious 

 collaboration in the struggle against parasites. 



Societies for the destruction of parasites have been formed in 



