xvi ANIMAL LIFE 



PAGE 



family — The life-history of the common gnat — The breath- 

 ing pores of the larva and of the active pupa — The emer- 

 gence of the rly — The development of the mosquito and its 

 relation to malarial fever — The life-history of the harlequin- 

 fly (Chironomus) — Its larva the 'bloodworm' — Variation 

 in its colour related to the nature of the water — The 

 phantom-larva of Corcthra — The life-history of Midges : the 

 owl-midge (Ccratopogon) — The black-fly (Simulium) — The 

 adaptations of its larva and pupa to life in running water — 

 The drone-fly (Erislalis) — Adaptations to larval life in stag- 

 nant water — General conclusions on the life-histories of 

 Diptera . . ........ 240 



The Hymenoptera : 



Efficiency of their care for their young — Complexitv of 

 their communal life — The less highly organised families of 

 this order — The saw-flies, gall-flies and ichneumons — The 

 nature of galls and their mode of origin — The two generations 

 of gall-flies — The solitary wasps — The key-hole wasp — The 

 nest and its stores of food — The sand wasp (Ammuphila) — 

 Mode of construction of its nest — Mode of capturing prey 

 and storing the nest — The social wasps — Their nests and 

 workers — Solitary bees — Prosopis a primitive type — The 

 burrowing and carder bees — Cuckoo bees . . . .263 



Evolution of the hive-bee — The lirst indications of 

 association in burrowing bees — The first attempts at comb- 

 construction — The appearance of workers at first casual in 

 Halictus, becoming a settled habit in bumble-bees — The 

 construction and ventilation of bumble nests foreshadowing 

 the perfect comb of the honey bee — The importance of good 

 seasons in assisting the evolution of the higher bees — 

 Behaviour of Arctic and Mediterranean bumble-bees — The 

 tropical Meliponas — The high degree of perfection attained 

 in the colonies of the hive-bee 2S4 



The nests of ants — The care of ants for their young — The 

 swarming of ants — Longevity of ant-queens — Foundation 

 of an ant-colony — Conditions that produce queens, drones, 

 or workers — Aberration of the nursing instinct . . . 294 



