138 NEW ZEALAND NATURE-STUDY BOOK 
Protective Colouring. A good lesson, or series of 
lessons indeed, can be given under this heading. Reference 
has already been made to several instances of protective 
colouring, and with a little trouble plenty of additional 
material can be collected, ¢.g., the colour of different kinds 
of larvae—of Grasshoppers, Moths, Butterflies, Cicadas 
—Beetles, etc. compared with the general colour-effect of 
their surroundings. The similarity of the curious Stick- 
insects to the twigs of trees is familiar to most people, 
whilst the way in which the larvae of many. insects 
surround their cocoons with pieces of bark to resemble the 
trees from which they are hanging, might be made use of 
as a further illustration of the need of protection when in 
the helpless pupa stage. 
Rearing of Insects. For an account of the best 
ways of capturing the various kinds of insects and after- 
wards of arranging them for a school museum the reader is 
referred to Hudson’s Manual of New Zealand Entomology, 
where the matter is fully dealt with. To this a few words 
may be added on the rearing of larvae. Subterranean 
larvae should be kept in moist soil ; aquatic larvae must be 
reared in an aquarium ; whilst carnivorous larvae must be 
supplied with flesh. Care should be taken to see that the 
food is fresh and the box well ventilated. Card-board 
boxes with glass covers and pierced with holes, or glass jars 
fitted with perforated lids are very convenient as cages. 
The bottoms of the vessels should be covered with moist 
sand or earth to hold the food plant of the larvae—an 
arrangement which serves to keep the food fresh and the 
air cool. It is sometimes necessary to place the plant-food 
in water; when this is done, care should be taken to cover up 
the vessel containing the water in such a way as to prevent 
the larvae from falling in and being drowned. 
