50 
Psyche 
[ March 
working continually, just like the fingers of a hand, to pre- 
vent it from turning towards its enemy. In such a position, 
with its back to the fly, the poor insect was unable to make 
any use of its sting, and all efforts to twist around were 
anticipated and prevented by the movements of the numer- 
ous sharp spines of the encircling tarsi. Some muscular 
effort is doubtless required to enable the fly to keep its 
hind legs in an extended and rigid position in spite of the 
struggles of the large, winged insect, which may account 
for their being larger and stouter than the others, with the 
femora being somewhat incressated and the tarsi being 
larger and more powerful. So intent was it upon securing 
its prey that I was allowed to examine its every movement 
minutely, and whilst wondering what would happen next, 
it suddenly put out its two mid-legs and caught the tips 
of each primary wing of the bee between the last two 
joints of the tarsus, in much the same manner as we should 
take hold of anything between our finger and thumb, and 
pulled them out to their fullest expanse, thus effectually 
preventing the last remote chance of escape by these organs 
of flight. The scorpion-fly was now hanging from the 
bush by its two arms, and holding its prey with extended 
wings and body still grasped by the hind tarsi. And now 
came the closing scene of this insect tragedy ; the hind legs 
slowly contracted to bring the body of the victim nearer, 
and the cruel, beak-like mouth approached, and, after hover- 
ing close to it for a few seconds, was inserted between 
the head and prothorax of the bee, which was unable to 
make the slightest resistance while its captor was pierc- 
ing and biting through the slender, fleshy neck.” 
Of all the Bittacidse, certainly the most curious is the Cali- 
fornian Apterobittacus apterus, which is completely devoid 
of wings and resembles a phylangid with a pair of legs 
missing. But this creature is nevertheless as successful 
at catching prey as its winged relatives. It replaces its 
want of wings by great dexterity in climbing, swinging 
itself monkey-like from twig to twig, often supported by 
one tarsus. Osten-Sacken (1882) once observed a speci- 
