556 



ANTS. 



the water-moat or the Forel arena. 1 prefer the latter, which 

 is very easily constructed. On a table or large board a circular or 

 elliptical enclosure a few feet in diameter is made by laying down a 

 wall of dry, po\\dered plaster of Paris about two or three inches broad 

 and an inch high. The inner edge of this wall is made smooth and 

 steep with the aid of a putty or case knife. The artificial nest, with 

 it> chambers moistened and darkened, is placed in this arena. Then 

 the colony to be installed, together with its brood and the earth of its 

 ne>t, i- dumped from the collecting bag into the arena just as it was 

 brought in from the field. The ants are at first much excited and 



FIG. 286. Combination Janet and Fielde nest used by the author. The roof- 

 pane of the light, or food chamber is removed, r. Plaster of Paris base cast in a 

 single piece ; c, entrance, to be plugged with cotton after the admission of the ants 

 'from the Forel arena ; m, glass roof-pane, resting on strips of Turkish towelling (s) ; 

 a, opening between the two chambers; n, manger, a cup-shaped depression in the 

 plaster base ; e , slice of sponge, which is kept wet. The plaster base measures 

 20 X 25 cm. and is heavily coated with varnish over its entire surface. 



wander about in the enclosure, but are unable to scale its crumbling 

 walls. They soon learn to avoid the powdery plaster, find the entrance 

 of the nest and migrate into it with their whole brood and any myrme- 

 cophiles they may have This migration is hastened by spreading out 

 the earth from their old nest so that it may dry. \Yhen the colony 

 has entered, the nest opening is plugged with cotton and the nest is 

 removed from the arena. Small colonies or colonies of small and deli- 

 cate species, which, as I have said, are best collected in bottles plugged 

 with cotton, may be hastily poured directly into one of the chambers 

 of the nest. By illuminating this chamber the ants may be induced to 

 move into the adjoining dark chamber and the fragments of the original 

 nest can then be removed. 



