36 EXPERIMENTS WITH CERTAIN DIPTERA. 



was kept alive for thirty days, so that blood is not necessary 

 to sustain life, though it may be for the production of 

 fertile ova. Although all the flies dissected were females, 

 very few were found to contain I'ipe ova and then usually 

 only one ripe ovum wat; seen in each ovary in spite of the 

 very large number of follicles present. 



Attempts to Infect Tabanids Artificially. 



1. On November 30th, 1918, seven T. circumdatus 

 and fiA-e striped tabanids T. mastersi and T. australicvs, 

 were given access to fresh nodules. These flies were 

 examined at intervals of from tAAo to four days but no 

 development had occurred. 



2. On December 30th, li>18, 20 T. circumdatus were 

 fed on a fresh nodule. These were dissected at intervals 

 of from one to ten days but no development had taken 

 place. In one a living larva was found in the intestine 

 one day after feeding, but in all other cases when found they 

 were dead. 



3. On April 4th, 1919, fifteen T. circumdatus were 

 fed on a nodule. These were examined at intervals of from 

 one to eight days, but no development had occurred. Id 

 one examined one day after feeding there were numerous 

 fairly large filarial embryos encysted in the fat body. 



4. On May 16th, 1919, one T. circumdatus was fed 

 on a nodule. It died next day but no live embryos were 

 seen. 



5. On January 8th, 1919, two T. dubiosus were fed 

 on a worm nodule. On dissection after two and three days 

 respectively, no embryos were seen. 



Total 43 T. circumdatus. 



5 Striped Tabanids ( T. mastersi and T. 



australicus) . 

 2 T. dubiosus. 

 Cleland, Dodd and McEachran (1917) failed to infect 

 calves, using Tabanus regis-georgii, Diatomineura inflata and 

 Silvius sp., also the mosquitoes Culicelsa vigilax and Stego- 

 myia atripes. 



Hill, McEachran and Dickinson did not detect larvse 

 in cattle ticks {BoopJiilus australis) ; Lyperosia exigua, 

 Stomoxys calcitrans ; Tabanus mas ersi and T. nigrifarsus ; 

 and the mosquitoes Myzorhynchus bancrofti, Culicelsa 



