Insects and Farasitic Diseases. 31 



this larva agreed with the one found in similar circumstances in 

 Experiment No. 7, and Avith that found under similar conditions 

 in Experiment No. 12 (see Fig. 20). 



B.rpen nienf 3 o. 9. 



This experiment, commenced on November 28th, was similar to 

 ^^o. 1, excepting that the end)ryos were obtained from three worms 

 only. Between Decendjer 4th and December 12th, 1 larva, 60 

 pupae and 25 adult flies were examined, none of which was found 

 to be infected. 



Erperiment Ko. 10. 



On December 3rd Experiments Nos. 7 and 9 were repeated, with 

 embryos from seven worms fed to four-days-old fly larvae. Subse- 

 quently 15 pupae and 55 adult flies of Musca. domestica were 

 -examined (December 17th and 20th), with negative results. 



On December 18th, finding that the faecal matter was still heavily 

 infected with living embryos of H. microstoma, then enclosed in 

 -sheaths, a number of two days old larval Stomoxys calcitrans were 

 liberated in it. Forty-four adult Stomoxys flies,' resulting from 

 these larvae, wei'e examined between January 7th and 10th, with 

 the result that 21 were found to harbour from one to three larval 

 Habronema each, while the remaining 23 were negative. 



As will be seen later (Experiment No. 13), the difference in age of 

 the larvae to which the embryos were fed cannot be supposed to have 

 "had any influence on the result here recorded for Experiment 10. 



ExjJeriment /To. 11. 



Embryos from about 30 gravid woinis were liberated in faeces 

 <;ontaining numeious five and six days old Musca domestica larvae 

 on December 14tli. Sixty-eight of the resulting fly pupae and 

 adults were examined between December 17th and 24th, none of 

 which was found to be infected. 



Exinriment ]^o. 12. 



F^mbryos from six giavid worms were liberated in faeces on 

 December 21st, and incubated at room temperature until December 

 24th, when a numl)er of Stomoxys larvae, then six days old, were 

 added to the culture. On Decend>er 27th a fly larva was examined 

 and found to harbour one end)ryo (see Fig. 20) comparable in 

 ^structure with those found in Experiments 7 and 8, with M. domes- 

 tica larva. Five pupae were examined on January 3rd and 4th, 



