330 THE WONDER OF LIFE 



be quite sufScient in itself — the workers discharging all 

 the tasks of food-getting, nursing, building and fighting. 

 When a mixed nest has been formed, the workers may 

 become semi-parasitic (as in the small Solenopsis), or may 

 be treated as the guests of the other species. This leads 

 on to slavery. But strangest of all are those cases where 

 there are no workers at all, but only males and females. 

 The fertile queen may be received into a foreign nest, 

 and the rightful queen may be killed instead of the 

 intruder. But this means sooner or later the end of 

 that nest, for there can be no further production of 

 workers. 



According to M. Pieron the primitive mode of nest- 

 founding is that in which the female is able to do it all by 

 herself. This is illustrated by Formica fusca, which is 

 probably an ancestral species, being indistinguishable 

 from Formica flori of the Baltic amber. A second stage 

 is exhibited in Formica rufa, where the female is unable 

 to found her nest unless she gets help from friendly workers 

 either of her own or of some diSerent species. Then follow, 

 in great variety of detail, the various stages of parasitism 

 and slavery. 



Among the many remarkable facts concerned with the 

 founding of a new colony, let us call attention to two of 

 the strangest. When a fertilized queen finds a suitable 

 shelter and begins to lay, she often has to eat a few of her 

 own eggs — ^to keep agoing. The others hatch into workers, 

 who are soon able to help the mother. But more eggs 

 may have to be sacrificed. If the female falls into a nest 

 of her own kind, she lays her eggs there, and the workers 

 tend the larvae carefully. But Miss Adele Fielde has shown 

 that if the tips of the workers' antennae are snipped off they 



