276 



tbis condition from the 19th to the 24:th and 25th of August." One lot 

 continued in tbe pupa state from the 7th to the 14th of August, another 

 from the 13th to the 20th of the same month. Observations and experi- 

 ments indicate that the eggs of this insect deposited on decaying ani- 

 mal and vegetable matter will hatch and come to maturity there. 



"All the natural openings of animals are liable to be attacked, par- 

 ticularly the sheaths of horses and mules and the navels of newly born 

 stock, while in all animals where an abrasion of the skin is made an 

 attack may be expected. 



" Among the svorst cases that have come under my observation were 

 when the horns of animals had been broken ; the maggots penetrated 

 the head, and when the animals were not at once attended to they soon 

 died. The majority of cases throughout the country resulted from the 

 deposition of eggs upon the animals in the vicinity of where ticks {Ixodes 

 hovis) had been killed, the flies being attracted by t|je blood. I have 

 observed that when sheep become sick and emaciated the odor charac- 

 teristic of sick sheep attracted the flies, and masses of eggs were deposited 

 in the folds of the wool and the young larvae penetrated the skin where 

 no wound had been made." 



From the fact that this insect has not been largely prevalent in this 

 State until this summer, which followed an exceptionally warm winter, 

 the author thinks that they are usually held in check by the cold of the 

 winters in that section. The burial of decaying" animal and vegetable 

 substances is advocated as a means of repressing the screw worm. 

 Experiments with chloroform, carbolic acid, corrosive sublimate, calomel, 

 ether, turpentine, kerosene, gasoline, and some patent remedies showed 

 that these remedies are more or less effective. Pyrethrum insect powder 

 and decoctions made with the leaves of various plants proved ineffective. 

 The author is inclined to prefer crude carbolic acid, which should be 

 applied of sufiicient strength to destroy the maggots. The wound should 

 then be washed with warm water and dressed with carbolized oil. . 



"To prevent the attacks of the fly there is nothing simpler or more 

 convenient than a mixture of tar and grease or fish oil smeared about 

 the parts ; so long as the smell lasts the flies do not seem to deposit 

 their eggs." 



Maryland Station, Special Bulletin, July, 1890 (pp. 48). 



Potash and paying crops. — A reprint of a compilation prepared 

 by the German Kali Works. 



