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Photo by the A-.ithjr 



INCIPIENT COLONY OF CARPENTER ANT {Campofiotiis pennsylvanicus) 



The queen has established her colony in the abandoned cocoon of a beetle (Rhagiuin 

 lineatum) under pine bark, has reared a few small workers, and has started a second brood, 

 represented by a small cluster of larvae in the upper part of the chamber (see text, pages 

 741-742). In incipient ant colonies the queen mother takes no food often for as long a 

 period as 8 or 9 months, and during all this time is compelled to feed her first brood of 

 larvae exclusively on the secretion of her salivary glands. 



Striking peculiarities which the ants have 

 developed during the long course of their 

 evolution, a word may be added in con- 

 clusion on the prospects of future de- 

 velopments. It must be confessed that 

 these prospects are not very bright, for, 

 strange as it may seem, there are no indi- 

 cations that these insects have made any 

 considerable evolutionary progress since 

 early Tertiary times. 



The exquisitely preserved ants of the 

 Baltic amber, belonging to the Lower 

 Oligocene formation, are in all respects 

 like existing ants. All of them belong to 

 existing subfamilies, most of them even 

 to existing genera, and a few of them are 



practically indistinguishable from species 

 inhabiting Europe today. That some of 

 them were herders of plant-lice is proved 

 by blocks of amber containing masses of 

 ants mingled with the plant-lice which 

 they were attending when the liquid resin 

 of the Oligocene pines flowed over and 

 embedded them. Possibly the soldier 

 caste is a recent innovation, but the differ- 

 entiation of the males, queens, and work- 

 ers was as extreme and precisely of the 

 same character then as now. 



This seems to force us to the conclu- 

 sion that all the great features of ant-life 

 must have been established during the 

 Mesozoic Age, and although many spe- 



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