CHAPTER VIII.

PARASITES THAT ARE FREE WHEN OLD.

Utility of Ichneumons--Scoliæ of Tan-beetles--Scolyti of Seychelles Cocoa-nut Trees--Elms at Brussels destroyed by Scolyti--Polynema in Eggs of Dragon-fly--Sphex--Platygaster-- Horse-fly--Livingstone--Animals in Paraguay destroyed by ix Hippobosci--Dipterous Parasites on Sheep and Stag--Gordius-- Shower of Worms--Eels in Ears of Corn 162