Cage Management 49 



determination of optimum temperature and the limits of tolerance for 

 many species, and has provided the means for maintaining any constant 

 temperature that may be needed for careful experimental work. 



Insufficient humidity is a most frequent cause of failures of cultures 

 of terrestrial animals. In the following articles will be found many means 

 of adding moisture such as sprinkling, burying in the ground, placing 

 inside the cage water-holding stuffs (filter paper, sphagnum moss, peat, 

 sponges, paper towels, fresh green leaves, etc.), conducting water inside 

 by means of wicks, dispersing it from porous earthenware containers 

 by capillarity, allowing evaporation from open pans, spraying it in the 

 cage, etc.* One of us (Lutz) even in keeping scorpions gives them a 

 shower bath from a bulb spray every day. Although they are desert 

 creatures they normally hide in relatively moist places except at night 

 or when the air outside their hiding places is moist. 



On the other hand, too much moisture may be fatal. It frequently 

 brings disaster by favoring the growth of molds. 



Sanitation. Keeping cages clean is very important. Sterilization of 

 containers by heat (steam, autoclave, etc.) and by chemicals is practiced 

 in many ways, and sterilization of food, drink, and shelters as well. 

 Wooden tubs are prepared for use by charring the interior in a flame. 

 Small containers are closed against infection by sealing the lids with vase- 

 line. Excreta and uneaten food require prompt removal. Cages of cer- 

 tain kinds may be washed, or they may be supplied with removable bot- 

 toms, or the floor may be covered with absorbent stuffs like sawdust or 

 sphagnum. 



Sick specimens must be isolated to prevent the spread of infection. 



Note: The following note concerning Pablum has been sent us by William LeRay 

 and Norma Ford, University of Toronto. "As a food for many invertebrate 

 and vertebrate animals, we are now using a pre-cooked cereal, devised in the 

 Research Laboratories of the Department of Pediatrics, University of Toronto, 

 and sold under the name of Pablum by Mead Johnson & Co., Evansville, Ind. 



"Insects which take dry food, such as ants, flour moths, etc., are fond of it ; 

 burrowing crayfish grow as rapidly on it as when living outdoors ; it is excellent for 

 earthworms, as well as for fish, birds, etc. To thrushes this cereal is particularly 

 acceptable. 



"Pablum consists of wheatmeal, oatmeal, wheat embryo, yellow cornmeal, pow- 

 dered beef bone, dried yeast, powdered dehydrated alfalfa leaf, and sodium chloride. 

 It has not only high nutritive value, but also furnishes substantial amounts of 

 vitamins A, B, E, and G, and essential mineral elements, calcium, phosphorous, iron, 

 and copper." 



* For chemical methods consult Spencer, Hugh M., Laboratory methods for maintaining 

 constant humidity. Internal. Critical Tables 1:67-68, 1926. 



