for a definite purpose and then no pains should be spared 

 to make the fulfillment of that purpose as complete as 

 possible. Many things contribute to this result. One which 

 requires special care is designing cases which give ade- 

 quate protection to specimens and at the same time de- 

 tract as little as possible from their appearance. Wherever 

 it can be done each side of a case should consist of one sheet 

 of glass only and the corners should show only as much wood 

 as is necessary. Since the lighting of exhibition rooms is pref- 

 erably from skylights or windows high in the wall, the tops 

 of cases should be made of glass. The doors must be dust 

 and insect proof at all costs. In order to facilitate a rear- 

 rangement of material at any time "unit" cases are often 

 used which are interchangeable throughout the museum. 



When skins are to be stuffed the very best taxidermy is 

 required to avoid mere caricatures which convey more 

 false than true impressions of the unfortunate animal. The 

 best mounting includes the reproduction of the typical en- 

 vironment of the animal. So bison are represented on a bit 

 of prairie and beavers in their forest haunts. In this work 

 there are many pitfalls for the novice and perhaps nowhere 

 is the difference between excellence and mediocrity more 

 conspicuous. When specimens are preserved in fluid many 

 shapes and sizes of receptacles are needed. Cylindrical jars 

 were formerly the only shape available but they distort 

 the appearance of specimens by acting as lenses. Recently 

 rectangular jars have been produced which obviate this dif- 

 ficulty. Snakes and worms coiled in bottles show only one 

 side and are often best displayed in tubes. Brilliantly colored 

 forms like squids, fishes, and lizards inevitably fade whether 

 they are stuffed or preserved in fluids. The most satisfactory 

 method of exhibiting these forms is by the use of casts and 

 models colored accurately from fresh specimens. The use of 

 models also gives an opportunity of getting more natural po- 

 ses and environment. In this way lizards can be shown on 

 typical desert rocks. Wherever this method is used the act- 



