34 



THE ARGENTINE ANT. 



of two pieces in the same manner as the ])latform, or to nail strips 

 across it at right angles to the grain. Both platform and base are 

 attached to the standard by long screws with heads countersunk. 

 Food is furnished by placing it on a piece of cardboard at any point 

 on the cover or platform. The base stands in running water, as 

 explained below. This type of cage permits the ants to leave their 

 nest witliin the cage and to forage over the platform, cover, and stand 

 in natm*al fashion, but their escape from the stand is prevented by the 

 very natural barrier of water, which they find when they approach the 

 bottom of the standard. It is not possible for them to conceal larvse 

 or eggs where the observer can not find them and they can not bring 



Fig. 8.— -Vrtificial formicary with parts assembled ready for use. (Senior author's illustration.) 



in larvfe or pupa' from outside sources to the annoyance and vexation 

 of the student. 



While the ants are very fond of sweets, we have found that sweets 

 alone will not suffice for food indefinitely. Animal food is also 

 required, and we find that by supplying the colonies with a ''balanced 

 ration" of honey and fresh beef or veal they will work in a perfectly 

 natural manner for many months without other food. 



The problem of confining the ants to the cage and its stand was not 

 so easily solved. We first tried Sir John I^ubbock's method of plac- 

 ing a moat of glycerine or water about the stand, but both liquids 



