Insects and Parasitic Diseases. 17 



of 22C. until noon on November 7th (eight days), when Musca 

 domestica larvae (two days old) were liberated in the vessel. On 

 November 20th and 21st fifteen flies were examined, ten of which 

 were infected with from two to fifteen larval Habronema each. 

 About half the total number of parasites were enclosed in cysts in 

 the abdomen, the remainder were free in tlie abdomen, thorax, or 

 head. 



Erperiment .Vo. 2. 



This txperiment was similar to No. 1, excepting that the embryos 

 were incubated for a period of 42 hours only (from 4 p.m. on 

 November 20th to 10 a.m. on November 23rd). The fly larvae were 

 of the same age and character as those used in Experiment No. 1 

 (i.e., two days old). Between November 26th and December 8th, 16 

 larvae, 12 pupae and 15 flies were examined, of which 1 larva, 1 

 pupa and 4 flies contained Habronema larvae. 



E rjyeriment No. 3. 



Embryos from 20 H. muscae were liberated in faeces with a 

 number of Musca domestica larvae ('tliree days old), at 3.30 p.m. 

 on November 26tli. Between December 4th and 10th, 29 pupae 

 and 12 flies Avere examined, of which 9 pupae and 5 flies were posi- 

 tive for Habronemic larvae. The infected pupae contained four 

 or five parasites each, and the infected flies two to twelve parasites 

 each. Twelve of the total number of parasites found in the flies 

 were enclosed in cysts. 



Exjyeriment No. If.. 



Embryos from numerous adult H. muscae were liberated in 

 faeces at 4 p.m. on November 2(Sth, with fly larvae then four days 

 old. Between December 5th and 7th 1 pupa and 38 flies were 

 examined, of which the pupa and 3 flies were positive. The pupa 

 contained five parasites. 



B. To determine the possibilit}^ of Stomoxys calcitrans acting" 

 as an alternative intermediary host. 



In both these experiments Musca domestica was used as a control 

 as to the vialiility of the Helminth embryos. 



Exjyeriment ^^f^- •'>• 

 Embryos from ten worms were incubated in faeces from December 

 21st to December 27tli, wiien larvae of Musca domestica and 

 Stomoxys calcitrans, which hatched about December 18th, were 



3 



