1910.J Measures for Destruction of Warble-Fly. 659 



should be kept separate. But while in principle the functions 

 of teacher and investigator may be different, in practice they 

 are closely associated, and no science teacher in a university 

 or college can now afford to neglect research. Those who 

 argue for the separation of education and research forget that 

 the teacher must continue to be a student, and that the adult 

 student who does not engage in original investigation of 

 some sort cannot be a very satisfactory member of a college 

 staff. 



Efforts have been made in recent years in several Con- 

 tinental countries * to free the cattle from the attacks of 

 warble flies by concerted action. 



Measures for the Various measures have been tried, but 



Destruction of the . u . u , , , 



tTr , , a the method which has proved most 



Warble-fly on the . . . 



Continent. efficacious and which has been used in 



most cases has been to examine the 



cattle before sending them out to pasturage in the spring, and 



squeeze out the maggots after making a slight cut in the 



warbles. 



To obtain the fullest possible measure of success the co- 

 operation of all the cattle-breeders of the district is necessary. 

 In Denmark a local agricultural society in Jutland has 

 carried on a systematic campaign since 1901. This society 

 each year divides all the cattle of the district into ten groups, 

 and places each group under the charge of a man, who is 

 employed to visit all the animals in his group from four to 

 six times during the summer and extract the maggots. A 

 special extractor is used for making the incision in the 

 warbles, and the slight wound thus caused heals much more 

 rapidly than the perforation made by the maggot. In 1902 

 22,394 warbles were extracted, at a total cost of £16 2s., 

 Or id. per head of cattle. From that time the number 

 of warbles decrease progressively, more than half of 

 those extracted in subsequent years coming from the small 

 number of animals that had been newly acquired. The 

 number of cattle treated has not varied greatly from year 

 to year, and the decrease in the prevalence of warbles is 



* Bulletin de la Soa'tit? National d? Agriculture, No. 3 and No. 6, 19 10. 



