Further than this, India and China are afraid of yellow fever because in both of these countries the stegomyia mosquito abounds.

The infection is considered to be at an end in a city three months after the last case, that being the lifetime of stegomyia.

In the same way Stegomyia occurs in some of the South Sea islands and yet there is no yellow fever there.

One mosquito may look very much like another, but the stegomyia and the anopheles differ in many important respects.