234 Nerve- winged Insects; Scorpion-flies; Caddis-flies 



concealed in sheltered places. They are active, though, when disturbed, and 

 look much like the larvae, but are more robust-bodied and bear externally 

 the developing wings. The head, with eyes and antennae, is more like that 

 of the adult. The complete metamorphosis of these insects seems very 

 simple compared with that of such other holometabolous insects as house- 

 flies and honey-bees. The adult female (Fig. 324) has a long, slender, 

 curved, pointed ovipositor, which probably is used to deposit the eggs in 

 deep, narrow, and safe cracks in the bark. But the oviposition has not 

 yet been seen, and the full life-history of the Raphidians has yet to be worked 

 out. 



The extraordinary-looking insect shown in Fig. 325 is one of the few 

 members of the Mantispidae, the sixth family of the Neuroptera. Its great 

 spiny, grasping fore legs and its long neck make it resemble its namesake, 

 the praying-mantis of the order Orthoptera, but its four membranous, net- 

 veined wings show its affinities with the Neuroptera. The fore legs are like 

 those of the mantis because Mantispa has similar habits of catching live 

 prey with them: it is a case of what is called by biologists "parallelism of 

 structure," by which is meant that certain parts of two animals become 

 developed or specialized along similar lines, not because of a near relation- 

 ship between them, but because of the 

 adoption of similar habits. The wings of 

 bats and those of birds show a general 

 parallelism of structure, although bats and 

 birds belong to two distinct great groups 

 of animals. 



Only two genera, viz., Mantispa and 

 Symphasis, of Mantispidae are known, and 



these include but five American species. 

 FIG. 325. Symphasis signata. (One . . f . 



and one-half times natural size.) SymphdSlS Stgnatd (Fig. 325) IS found m 



California, while of the four species of Man- 

 tispa three are found in the East and South, while one ranges clear across the 

 continent. But they are insects only infrequently seen, and each captured 

 specimen is a prize. The life-history of no one of our species has been studied 

 an opportunity for some amateur to make interesting and needed observations 

 but Brauer has traced the life of the European species, Mantispa slyriaca, 

 and found it of unusual and extremely interesting character. The following 

 account of Brauer's observations is quoted from Sharp (Cambridge Natural 

 History, vol. v): "The eggs are numerous but very small, and are deposited 

 in such a manner that each is borne by a long slender stalk, as in the lace- 

 wing flies. The larvae are hatched in autumn; they then hibernate and 

 go for about seven months before they take any food. In the spring, when 

 the spiders of the genus Lvcosa have formed their bags of eggs, the minute 



