406 WILLIAM M. MANN 



columns of workers outside the nest during the second year, and 

 Emery considers it possible that marriage-flights may depend 

 on the number of sexual forms, especially of males. Where there 

 are only a few of these copulation takes place in the nest. 



In founding a colony, one or more Polyergus queens enter 

 the nest of Formica fusca or some variety of that species. 

 When not prevented by the workers the parasitic queen goes 

 directly to the fusca queen and kills it by piercing its brain 

 with the sharp mandibles. The demoralized fusca workers then 

 readily adopt the alien queen. Some of the Polyergus were 

 killed by fusca workers before reaching the queen. This was 

 in a Janet nest, which is particularly favorable to the Polyergus 

 queen. In nature the killing of parasitic queens probably occurs 

 more often. 



It is important to Polyergus that the host colony be popu- 

 lous. This Emery believes to be true of all parasitic ants. If 

 the colony selected by the queen is small, the primitive stage 

 of the Polyergus colony may last two years. During the first 

 year no eggs are deposited. The second year eggs are laid and 

 workers develop, but no raids are started until late in the 

 summer, sometimes not until the third year, when the colony 

 is fully developed. 



Emery (19) studied the relations of fecundated females of 

 Pheidole pallidula toward each other. They oviposit a few days 

 after fertilization, and when placed together in an artificial nest 

 fight and tear the antennae and legs of one another. The indi- 

 viduals without antennae become indifferent to the eggs, so 

 that their care falls to the lot of the female that has preserved her 

 appendages. Eggs laid early in July gave rise to workers August 

 15th. After three separated females had been permitted to 

 bring up their broods, Emery made openings between their 

 cells. The workers at first tried to obstruct the openings. The 

 workers of two of the colonies fought with one another. When 

 the queen of one of these was killed her brood was appropriated 

 by the other. Later the two remaining colonies behaved in 

 the same manner till only one female remained and the broods 

 of all three colonies were united. When several females were 

 permitted to found their colonies in close proximity to one 

 another, similar results were obtained. Emery concludes that 

 recently fecundated queens of Ph. pallidula live together amic- 



