Natural History 531 



Prosperity is succeeded by starvation. There are no stores to 

 fall back on, and deadly numbness and demoralisation break 

 down the orderly routine of the nest. The exhausted workers 

 die in their thousands, and with them the parent queen. None 

 but the young royalties survive, and the males only long enough 

 to mate with the young queens; thereafter they also die. The 

 young queens destined to found new colonies next spring alone 

 escape the common fate, but the demoralisation shows itself in 

 them too, for they devour the remaining eggs and larva?, and on 

 this rather cannibal fare they are able to survive the winter. 



6 



LIFE HISTORIES 

 Story of Cabbage White Butterfly 



The food of Insects is extremely varied, not only in different 

 species, but also within a single life-history, and it naturally fol- 

 lows that there is much variety in the ways of obtaining it, and, 

 in particular, in the structure of the appendages associated with 

 the mouth. Insects depend greatly on their sense of smell wher 

 in search of suitable food, and the organs of smell, minute olfac- 

 tory pits or bristles, are found chiefly on the antennae. Some 

 insects move their feelers markedly on coming near strong-smell- 

 ing substances, and some are unable to find their appropriate 

 food without the aid of their antennas. For instance, Carrion 

 Beetles which had had their antenna? removed were found to be 

 incapable of locating their evil-smelling food. A very striking 

 example of change of diet is seen in the life-history of a butterfly, 

 such as the common Cabbage White Butterfly. The small, sculp- 

 tured eggs are laid in large numbers on the plant which is to form 

 the food of the caterpillars. The caterpillar emerges from the 

 egg as a worm-like, short-legged little animal, green against the 

 green of its natural haunt, with simple eyes, short feelers, stumpy 

 abdominal "pro-legs" in addition to the three pairs of jointed 



