SURROUNDINGS OF GROWING INSECTS 237 



and characteristic. Even among the saw-flies there are 

 remarkable instances of such habits. A Tasmanian species 

 (Perga Lewisii] lays her eggs between the two surfaces of an 

 eucalyptus leaf on which she remains until the eggs have 

 been hatched. Then she follows her little caterpillars about 

 as they feed on the foliage, often overshadowing them with 

 her body, ' ' preserving them from the heat of the sun and 

 protecting them from the attacks of parasites and other 

 enemies ". 



In the brief survey already given (p. 228) of the habits of 

 the digging wasps, it has been seen how from the storing of 

 nests with prey paralyzed by stinging, alongside which the 

 eggs are laid perhaps the most striking example among 

 insects of anticipatory parental care we are led on to such 

 behaviour as is shown by Bembex, whose female not only 

 provides, when laying her eggs, victims for the larvae as yet 

 unhatched, but herself tends and feeds these larvae in the 

 later periods of their growth. Thus is suggested a transition 

 to the care for growing larvae that is displayed by the most 

 highly developed of the Hymenoptera wasps, bees, and 

 ants. The great majority of the bees have the habit of 

 laying their eggs in chambers alongside a store of food, which 

 is provided beforehand by the mother for the offspring that 

 she will not herself see. The food of bee grubs consists of 

 floral products : honey and pollen, the latter being gathered 

 by the mother from blossoms, while honey is nectar that has 

 undergone digestion within the bee's crop (or "honey-stomach ") 

 and has been regurgitated into the comb-chambers. This, 

 and the cultivation of fungi, are perhaps the most specialized 

 modes of vegetarian feeding practised by insects. The care 

 of the mother-bee for her unseen offspring is shown by the 

 elaborate constructional work on the chambers in which the 

 larvae live and feed. Thus, the leaf-cutter bees (Megachile) 

 cut, with their mandibles, neat pieces from rose and other 

 leaves, with which they line the underground chambers of 

 their nests. The mason-bees (Chalicodoma) of southern 

 Europe make chambers with strong, substantial walls of 

 cement formed of earth and small stones compacted with the 

 insect's saliva ; through this wall the young bee has to bite its 

 way out with its mandibles when the transformation is 



