22O ADELE M. FIELDE. 



Forel's method of making, upon a table, a stockade of dry 

 plaster of Paris, to prevent the escape of the ants deposited 

 within it, serves well when large colonies are dealt with. But 

 ants have high regard for personal cleanliness and are discom- 

 forted by the adhering dust which punishes their effort to escape 

 over this stockade. The Lubbock island renders clean stock. 



The Janet nest, a series of four pits in porous stone, cement or 

 stucco, with water in the pit at the end opposite the food-pit, 

 proved that the ants may live healthfully without earth ; showed 

 the practical value of more than one compartment in the artificial 

 nest ; and gave an excellent background for viewing the ants. 

 But the Janet nest is cumbrous and weighty ; and its food room 

 becomes quickly mouldy in hot weather. 



The glass nests are constructed at less expense than are those 

 of either the Lubbock or the Janet pattern ; they are easily kept 

 clean, and the small space which they occupy, with their very 

 light weight, greatly facilitates the bringing of the ants under close 

 observation. 



THE MARINE BIOLOGICAL LABORATORY OF WOODS HOLL, MASS., 

 July, 1904. 



