Photo by C. G. Hartman 



NEST CHAMBER OF A SMALL TEXAN FUNGUS-GROWING ANT (MycetOSO)'itis hartmatli) 



The middle chamber of the preceding figure one-fourth larger than natural size, showing in 

 the upper right-hand corner some of the rootlets to which the garden is suspended 



their brood, or to excavate the nest, and 

 are therefore compelled to keep kidnap- 

 ping the young of the host species in 

 order to secure the performance of these 

 tasks. The other method is by com- 

 pletely suppressing the worker caste in 

 the parasitic species, so that the queen 

 after her adoption in the nest of the alien 

 species can at once produce males and 

 females within the host colony's lifetime, 

 which is very short because the host 

 queen has been eliminated. 



These various methods of colony for- 

 mation show that among ants the ex- 

 treme adaptations of parasitism have for 

 their sole object the securing of better 

 opportunities of reproduction. 



The restriction of reproduction to a 

 few members of the colonv brousht with 



it, among other advantages, the usurpa- 

 tion of the nutritive and protective func- 

 tions by a special caste, the workers, 

 which, moreover, comprised the majority 

 of the personnel of the colony. Later 

 these functions were delegated to two 

 subdivisions of this caste, the workers 

 proper and the soldiers. 



Among the special adaptations for the 

 protection of the colony we may cite the 

 development of the sting and of the vari- 

 ous poisonous or malodorous secretions 

 with which the workers spray or smear 

 the bodies of their enemies, the enlarged 

 mandibles of the soldiers, and above all 

 the excavation or construction of the 

 nest, which protects the colony both from 

 its enemies and from excessive drought, 

 cold, and heat. 



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