xvi CONTENTS 



hosts to complete their life-cycle The sheep-tick Various 

 animal parasites, beneficial and otherwise Study of parasites 

 offers a prodigious field for scientific work . Pp. 157-183 



CHAPTER VIII 

 INSECT WEAPONS AND TOOLS 



Many insects which can inflict serious injury with their weapons 

 The gad-fly Personal experience of the effect of its 

 weapons The malarial mosquito The weapons of the 

 wasp The spider's poison fangs and teeth A fly's foot 

 The foreleg of a diving beetle Feathered oar of a water- 

 boatman Poison bag and sting of wasp An insect armed 

 with a bayonet The saw-fly's weapons Every insect has 

 some special weapons to suit its own particular purposes 



Pp. 184-206 



CHAPTER IX 

 MAY-FLIES AND THEIR NEIGHBOURS 



Insect life at the bottom of the pond Aquatic insects spend the 

 greater part of their lives beneath the water The May fly 

 as the type of brief and ineffectual life Their anatomy 

 Their graceful and buoyant movements Life story Extra- 

 ordinary final emergence The alder-fly Caddis-flies The 

 wonderful cases built by the caddis-grubs Dragon-flies 

 Mask of the dragon-fly larva Strength of wings Eating 

 butterfly . . Pp. 207-233 



CHAPTER X 

 WONDERFUL TEETH AND TONGUES 



The mouth of a snail is provided with teeth unlimited Genera 

 and species identified by the various characteristic, dental. 



