METHODS OF COLLECTING AND STUDYING ANTS. 555 



by a single thin block of colored plaster of Paris, but the height and 

 arrangement of the chambers, their communications, the towelling 

 and roof-panes are those of the Fickle nest. Other details of construc- 

 tion may be readily inferred from an examination of Fig. 286 and 

 its legend. 



Miss Edith Buckingham (Amer. Natur., Oct., 1909, pp. 611-6^.4) 

 has described a nest of the Fielde pattern, in which the weight is 

 greatly diminished by replacing the glass base by one made of sheet 

 aluminum. 



Dr. F. Santschi has given me directions for making a nest which 

 he has used with excellent results in his studies on small ants, such 

 as O.vyopomyrmex, Lcptotlwi-a.r, Monomorium, Tapinoina and the 

 parasitic Bothriomyrmex and Wheeleriella. It is quickly constructed 

 merely with wet plaster of Paris and glass plates, such as those used 

 in photography. Onto the surface of a plate of the required dimen- 

 sions the plaster is poured in the form of the walls of two oblong or 

 square chambers and a short connecting gallery. Then another plate 

 of the same dimensions, with its surface oiled, is pressed down some- 

 what onto the plaster before it sets, leaving a space of a few milli- 

 meters between the two plates. As soon as the plaster has set, the 

 upper plate is removed and may be cut into two pieces to serve as the 

 covers of the chambers. The plaster is sufficiently porous to admit 

 the air, and the walls leave no spaces for the escape of the ants. This 

 nest is so shallow that it can be placed on the stage of the compound 

 microscope and its inhabitants studied under a low objective. 



All of the various artificial nests here described have both admirable 

 qualities and serious defects, so that anyone who wishes to gain a 

 thorough knowledge of the ants will do well not to pin his faith to any 

 one c,f them, but will select the form best adapted to the special problem 

 in hand. For small colonies very simple nests consisting of Petri or 

 flat stender dishes will often answer every purpose. In all nests, how- 

 ever, there should be plenty of moisture, food and fresh air, as ants 

 soon sicken and die when the supply of these essentials is insufficient. 

 The food should be varied. Fresh insects and honey are nearly always 

 acceptable. I have kept colonies for many months on a thick mixture 

 of raw yolk of egg. honey and sugar, with an occasional mess of hashed 

 meal-worms, or of the larvae and pupae of alien ants. The harvesting 

 ants (Po(jououi\nnc.\', Pheidole) are fond of our various breakfast 

 foods, but these species also thrive best on an occasional diet of fresh 

 insects. 



Ants are readily induced to move with their brood into the nests 

 of the Lubbock, Janet and Fielde patterns. This is accomplished by 



