OBSERVATIONS ON INSECT LIFE 167 



the overhanging bank. Thus do the crabs, though 

 the most sluggish creatures in the pool, gain their 

 livelihood by a subtle skill. I suspect it is similar 

 in the depths of the ocean, and that there the crabs 

 and lobsters lie in hiding amongst the sea-weed and 

 the stones to pounce suddenly upon their prey. 



Dragon-flies (Odonata) and sometimes robber-flies 

 (Asilida) loved to haunt the streams. The dragon- 

 flies came, not only for prey, but to lay their eggs 

 in the water. One large and beautiful species, with a 

 black and green thorax and banded abdomen, used to 

 alight on the grass and dip its abdomen deep down 

 into the water ; while its partner, hovering just above, 

 dashed furiously to attack any strange dragon-fly that 

 dared to invade the sacred precincts. Dragon-flies 

 must be included amongst the few enemies of ants. 

 After a heavy downpour of rain flights of male and 

 female ants belonging to a small yellow species used 

 sometimes to congregate in a cloud and hang in 

 the air near the banks of the streams. The dragon- 

 flies then took a heavy toll of their numbers, darting 

 hither and thither through the swarm like a flock of 

 insectivorous birds amongst a flight of termites. 



The Asilidce used to lie in wait for prey usually on 

 a projecting spur of limestone. These flies, as is well 

 known, capture insects on the wing, drive their sharp 

 beaks into the bodies of their victims and suck up 

 the body-juice. In dealing with smaller prey, such as 

 a house-fly or a Syrphid, it simply drives its beak 

 straight into the abdomen of its victim. No more 

 cunning is required. This is sufficient to subdue 

 its capture. But it is different with stronger species. 

 I watched an Asilid that had seized a moth. The 



