70 



ANIMALS OF LAND AND SEA 



form the food of many flies, especially the small headed hunch- 

 backed spider flies. As grubs these live within the spiders or 

 within their egg cocoons eating the eggs. These flies are 



rather rare; but one 

 of the small wood 

 wasps chiefly uses 

 them to provide food 

 for her young. 



One does not or- 

 dinarily regard the 

 butterflies as fero- 

 cious creatures, 

 though in the Ameri- 

 can tropics the pug- 

 nacious squeaking 

 butterflies when fly- 

 ing about you and at- 

 tempting to frighten 

 you away may cause 

 you mild surprise. 

 In our own woods, 

 too, in the early 

 spring the common 

 mourning-cloak 

 which also chirps, 

 though faintly, will 

 sometimes fly di- 

 rectly at you, and 

 not infrequently you 

 see it darting at the 

 smaller birds. 



Few insects are more extraordinary in their habits than the 

 lycaenid butterflies, the group to which belong our httle hair- 

 streaks, blues and coppers. Of most of these the caterpillars, 

 which are small and slug like, have on the back a honey gland 

 opening on the eleventh segment. On the segment just behind 



Figs. 50, 51. A Skate, and a Liparid. 

 For explanations of the figures see p. xiii. 



