COLLECTING AND PRESERVING INSECTS RANKS. 



113 



larvae as attractive as even the study of the minute details of struc- 

 ture in the adult insect. In no branch of natural history are life 

 histories more readily studied than in insects. The ease with which 

 the caterpillars of many butterflies and moths may be kept in cap- 

 tivity make them the most suitable subjects for experimentation in 

 many lines of biological inquiry. As in collecting so in rearing, the 

 simplest apparatus is usually the best. However, different groups 

 respond better to different treatment, and there are many wrinkles 

 in the handling of living material that can only be obtained by long 

 practice. 



For many caterpillars almost any sort of a wooden box, with some 

 sand in the bottom and covered with mos- 

 quito netting, will make a suitable rearing 

 cage. Branches of the food plant can be put 

 in each day, the moist sand keeping it fresh 

 until the next day. Tight boxes may be 

 used, provided they are kept clean. For 

 small insects glass jars or jelly glasses are very 

 useful, and many species can be reared in ordi- 

 nary glass test tubes, plugging the top with 

 a bit of cotton. A pot cage is readily made 

 by taking a flower pot with soil in which 

 there is inserted the plant, and over the plant 

 an ordinary lamp chimney, pressing it down 

 well into the soil and covering the top with 

 netting. (See fig. 169.) By pouring water 

 into the saucer of the flowerpot the plant 

 may be kept moist. Mr. Foster has modified 

 the plan slightly by using a tin can of earth 

 containing a bottle of water in the center, the 

 top of the bottle even with the top of the soil. 

 The plant or branch is placed in the bottle 

 and about its base a wad of cotton, so the 

 larva can not fall into the water. Over the plant is placed a glass 

 Welsbach gas chimney covered with netting. 



A more elaborate breeding cage utilized by Doctor Riley is shown 

 in the illustration (fig. 170). The box is of wood, with a removable 

 to}) covered with wire netting. The sides are of glass, or may also 

 be of wire netting. One side is made into a door. The cage can be 

 placed on a zinc base made as in figure 171. This cage may be made 

 any size. A convenient one is 12 inches square and 18 inches high. 

 The inner box of the metal vase has holes in it so that water put in 

 the outer box will moisten the sand in the inner box. The branch or 

 plant may be put in the top "eZ" with a wad of cotton to hold it in 

 place. Many species will breed in almost any situation, but with 



Fig. 169.— A lamp chimney cage. 



