ANTS AND THEIR GUESTS WASMANN. 457 



1.— ORGANIZATION OF THE ANT SOCIETIES. 



The simple ant colony represents a family in the narrower or wider 

 sense. It comprises one or more generations of the descendants of 

 one or more females of the same species of ant. The tribal mother 

 is the fertilized queen, who has founded the colony. The descend- 

 ants arc in part wingless forms of the female sex, the so-called workers, 

 in part young winged males and females, and in part also others, still 

 young, though akeady fertilized and deiilated, queens. The worker 

 cast may again divide itself into different forms, namely, into true 

 workers and into soldiers, which latter are distinguished from the 

 workers by the prodigious structure of their heads or mandibles. 

 Soldiers occm* among our Palearctic ants only in a few genera 

 (Colobopsis, Cataglyphis, Pheidole). The workers themselves can 

 again divide into large and small individuals, of which the former are 

 sometimes, as for example in Camponotus, veritable giants in com- 

 parison with the latter. This dimorphism is much further developed 

 still in exotic genera, like Pheidologethon. In some sjjecies of ants 

 there are found at the side of the winged females, which shed their 

 wings only after pairing, wingless true females as well, the so-caUed 

 ergatoid queens. A typical example of these, which was already 

 known to Peter Huber, is offered by the amazon ant (Polyergus 

 rufescens) (compare fig. Sa).^ In the tropical legionary and driver 

 ants (Eciton and Dorylus) even wingless females alone occm-, and 

 moreover of relatively enomious size. In some species of ants there 

 is even a manyfold pleomorphism of the females which finds expres- 

 sion in different transitions between females and workers. Much 

 rarer are the wingless, and then mostly workerhke (ergatoid) males; 

 they are known in but few species of ants, and occur either along 

 with the normal winged males or as the only male form. i\ji example 

 of the last kind is shown in the shining guest ant, Forrnicoxenus niti- 

 dulus (fig. 1), where the males, on account of their great similarity to 

 the workers, remained unnoticed 38 years, until Adlerz discovered 

 them in 1884. 



With many species of ants one can find several queens together in 

 the same colony. With oui" hill ant, Formica rufa, their number in a 

 single nest may even reach toward 100. Furthermore, an ant colony 

 may possess several nests, which are simultaneously or alternately 

 inhabited. So-called seasonal nests, which are changed ac(;ording to 

 the time of year, have been observed, for example, in Fonnica san- 

 guinea and Frenolepis longicornis. By the plurality of queens in a 

 single colony the ant states differ strikingly from the states of the 

 honey bees. The latter bear by comparison more a monarchical, the 

 former a repubhcan character, since the queen with the ants forms 



'The figures 1 to 33 are arranged on plates 1 to 10. 



