7 o 



some Anopbelines with, ripe ovaries are placed. Observe 

 that ova are laid upon the mud. 



7. Preserve the mud for forty-eight hours, pre- 

 venting it from becoming completely dry. 



At the end of forty-eight hours or more, remove 

 a few ova to a dry slide, and place under a low power. 

 Allow a drop of water to flow on to the ova. Observe 

 the escape, within a minute or so, of the young larvae, 

 and the fact that a cap-like piece of the egg-shell is 

 pushed off. 



8. Observe that Anophelines kept in a dry test 

 tube will occasionally lay their eggs on the side of the 

 tube. 



9. Note the time when the eggs were laid and 

 the time at which the larvae emerge. This depends 

 greatly on the temperature. It may take two or three 

 days. Ce. argyrotarsis, one-and-a-half days (Taylor). 



10. Remove Anofheline ova on paper and allow 

 them to dry, and note that after two, or three days 

 (86-96 F.) at the most, they will not hatch when 

 carefully placed in water. 



