turtle, or a snapper of any age, its long tail is likely to leave its mark also. The 

 dainty, spider-like prints of frog or toad hands and feet are sometimes visible, 

 where it has journeyed from pond to pond. Even the clams crawling on the 

 lake bed leave telltale furrows, and a silvery ribbon of mucus shows where 

 the snail or slug has wandered. 



On the fine sand of dunes and deserts tracks are often abundant. Many 

 of them are likely to be insect tracks, especially beetles. Six legs, some pushing 

 and some pulling, often leave most curious and complex, lacework paths. The 

 sand'dwelling lizards usually have long, widely spread toes, which leave 

 puzzling designs. The puzzle increases when the series starts and stops 

 abruptly, unless one remembers that some of these animals may dive into the 

 sand for shelter and may "swim" through it below the surface for several 

 feet. As with mammals, the tail may be dragged at low speed, but is often 

 held aloft when the pace quickens. Snakes often leave definite tracks in sand. 

 Rattlesnake hunters often profit by the crepuscular habits and follow up the 

 trails in the early morning. Most snakes leave a sinuous furrow, the direction 

 of travel indicated by the sand piled up at the back of each curve. The side- 

 winder, a desert rattlesnake, leaves a series of diagonal but unconnected, 

 straight furrows, the direction of travel indicated by a hook at the rear end 

 of each furrow. 



Tracks can usually be photographed to show details only when the sun 

 strikes them at such an angle as to leave definite shadows, which happens only 

 in early morning or late afternoon when the light is seldom bright enough for 

 good pictures. If one has sufficient patience, lamp black or similar fine powder 

 may be sifted into the depressions and, if the wind permits, good pictures 

 obtained when the sun is high — but a calm day, a steady hand, and extreme 

 care and patience are required. For snow pictures a yellow filter aids in re- 

 cording contrasts. 



Casting in plaster is the best method of preserving or duplicating individ' 

 ual animal autographs, the original mold being done either in plaster or in wax. 

 The chief difficulty usually lies in deciding which particular print best shows 

 all the desired details. The easiest method is to find the tracks in mud and, 

 by the aid of candle ends, to fill one with melted wax. As soon as the wax has 

 hardened, it and some of the mud around it can be taken up and carried home, 

 where the mud can be removed by gently washing in cold water and brushing 

 with an old toothbrush. Then the wax block or mold should be inverted and 

 slightly sunken in a bed of fine, wet sand, and retaining walls built around 

 and backed by more wet sand. Sections of paper cartons, such as are used 

 for packing salt or ice cream, make excellent walls, although pieces of card- 

 board will serve, if well banked with damp sand on the outside and at the cor- 

 ners. A quantity of water about equivalent in bulk to the size of the cast 

 desired is now taken and plaster-of-paris sifted in until a mixture about like 



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