596 



THE AMERICAN NATURALIST 



[Vol. XLVI 



sort of device for its protection is essential. The plan 

 that I have found most successful lias been to place bird 

 cups in the nest box so that the mouse can procure the 

 food through an opening in the front of the box. The 

 cups are further provided with an apperture in the top 

 through which, without opening the case, food may be 

 added. This method of feeding, by preventing the mouse 

 from running over the food, holds in abeyance the spread 

 of disease. 



The most satisfactory food that I have used for mice is 

 wheat, added to which is a small amount of stale bread. 

 These, together with milk— which is given by a modifica- 

 tion of the method below described for water— constitute 

 the daily and constant diet. Occasionally sunflower seed 

 and a few leaves of lettuce may well be given for a change. 



4. Water Receptacles.— The inverted bottle which is 

 now in general use for supplying water has done much to 

 eradicate ills resulting from a bad water supply. By this 

 device a large quantity of water can be provided which is 

 a great advantage in general cultures. In many kinds of 

 experiments, however, it is desirable to keep water in 

 greater purity than is possible even by this method. To 

 do this I have found a device which is strikingly simple 

 and at the same time singularly effective in that it keeps 

 the water in contact only with glass. My plan consists in 

 closing the end of a specimen-tube (or test-tube) in a 

 frame so that the opening is just large enough to retain 

 the water drop when the tube is filled and inverted in the 

 case. 3 These inverted tubes are inserted through holes 

 made in the top of the case and are prevented from fall- 

 ing through by means of small rubber bands placed 

 around the closed ends of the tubes. The tube mar then 

 be removed and refilled without opening the case, the 

 refilling being done from a siphon bottle. 



I he addition of these devices for food and water to a 

 mesh-bottom case I have found to aid much in the inten- 



