TENACITY OF LIFE IN ANTS. 3OI 



kept were frequently cleansed with 80 per cent, alcohol, and only 

 distilled water was used in wetting the enclosed sponges. Care 

 was taken to maintain hygienic conditions at all times during the 

 life of the ant. In these experiments a Stenamma fulvum worker 

 lived ten days without her head. A Formica subscricca worker 

 lived fifteen days without her head. Of seven decapitated Cain- 

 ponotus pennsylvanicus workers, three lived five days ; two lived 

 twenty-one days ; one lived thirty days ; and one lived forty- 

 one days. The last two mentioned were the largest, being thir- 

 teen millimeters long. After decapitation, they were kept for 

 four days at a temperature of about 10 C. or 50 F. and after- 

 ward in the natural summer temperature of the laboratory. 1 The 

 ant that lived forty-one days after decapitation walked about in 

 the cell until two days before her death, and during the last two 

 days gave evidence of life by a twitching of the legs when I 

 touched her. 



SUBMERGENCE. 



While making experiments in June, 1904, with a view to as- 

 certaining how long ants could live under water, 2 I came to sus- 

 pect that the death of ants submerged less than seventy-two 

 hours was caused by bacteria rather than by deprivation of oxy- 

 gen. Later in the summer I therefore made further experiments,, 

 merging the ants in distilled water, and keeping them in the 

 dark at a temperature of about 10 C. or 50 F. Under these 

 conditions the ants survived much longer periods of submergence. 



Of eighteen Stcnannna fii/rniu submerged four days, seven- 

 teen revived and twelve fully recovered. 



Of fourteen Stenamma fulvum submerged six days, six revived, 

 and one fully recovered. 



Of twelve Stenamma fnlvnin submerged eight days in sixty- 

 five cubic centimeters of water, seven revived and fully recovered. 



Of seven Cainponotus pennsylvanicus submerged eight days, 

 four revived, fully recovered, and were returned to their old 

 associates. 



1 Nearly all the experiments recorded in this paper were made at the Marine 

 Biological Laboratory at Woods Holl, Mass., during the summer and autumn of 1904. 



52 "Observations on Ants in their Relation to Temperature and to Submergence," 

 A. M. Fielde, BIOLOGICAL BULLETIN, Vol. VII., No. 3, August, 1904, p. 170. 



