107 



Several attempts were made to inoculate the larvae beneath 

 the skin by means of a hypodermic needle and syringe. It was 

 found to be difficult or impossible to determine whether the larvae 

 had been successfully inoculated, and as only a fleeting infiltration 

 of the tissues occurred after inoculation, the method was 

 abandoned. 



2. Experiments with H. muscae : — 



(a) Larvae placed in the skin of the horse — • 



Six proboscides of Musca domestica heavily infested with 

 larvae were placed in an incision in the skin of the mare, and 

 removed five to six hours later. Tumefaction of the tissues was 

 produced, which increased during the twenty-four hours after 

 inoculation, and then gradually subsided. About a week later a 

 swelling about the size of a Barcelona nut was present. This 

 rapidly reduced in size and completely disappeared. 



The day following the first inoculation another inoculation 

 was made with the same results as the first. 



Some days later three more inoculations were made. After 

 the primary tumefaction of the tissues had disappeared in from 

 twenty-four to forty-eight hours no abnormality could be detected. 



These experiments were repeated on the pony. In all, three 

 inoculations were made. Only a slight primary tumefaction of 

 the tissues resulted which disappeared in about thirty-six hours, 

 leaving only a very slight thickening, which completely dis- 

 appeared in from fourteen to twenty-one days. 



(b ) Larvae added to the conjunctival sac — 



About the same time as the above experiments were made 

 larvae were placed in a pipette containing a mixture of equal 

 parts of normal horse serum and normal saline solution. The 

 larvae were then added along with a small quantity of the mix- 

 ture to the conjunctival sac (off side) of the mare. The conjunc- 

 tiva remained normal in appearance, and no excessive lacrymation 

 was produced. 



The experiment was repeated on the pony. The following 

 morning a slightly excessive lacrymation was present, which, 

 however, disappeared during the next twenty-four hours. The 

 conjunctiva remained normal in appearance. 



(c) Larvae placed on a scarified area of skin — 



An area of the skin of the mare was lightly scarified, and 

 the proboscides olaced on the moist surface, and kept in place 

 by the aid of adhesive plaster. The tissues showed very slight 

 tumefaction twenty-four hours later, which rapidly disappeared. 



This experiment was repeated with the same result. 



It was also repeated on the pony, and no reaction was 

 produced. 



(d) Larvae placed on a moistened area of skin — 



A shaved area of the skin of the mare was moistened with 

 the serum and saline mixture, and a proboscis containing larvae 

 placed on this. The following morning there was the merest 

 suggestion of an elevation in the skin, but it was not observed 

 the following evening. JThis experiment was repeated with the 

 same result. 



There was no reaction produced in the tissues to suggest that 

 the larvae has penetrated the skin. 



