CHAPTER XVI. 



THH HARVKSTING ANTS. 



" Verrit letra bouni grau formica labores 

 Et caveis fruges turba nigella locat, 

 Quamlibet exiguo videatur pectore, sellers, 



Quo legat hibernse commoda grana fami. 

 Hanc juste famulam nigri jam dixeris Orci, 



Quam color et factum composuit domino. 

 Namque ut Plutonis rapta est Proserpina currn, 

 Sic formicarum verritur ore Ceres.'' 



" Anthologia Latina," 104. 



The two preceding chapters contain an account of the primitive and 

 carnivorous species which represent the savage and hunting stages in 

 the development of ant societies. In this and the following chapter I 

 shall endeavor to sketch the habits of certain ants that have largely 

 abandoned entomophagy and have taken to a benigner, vegetarian diet. 

 I have called attention (p. 176) to the fact that abundance of food is 

 necessary to the maintenance of social life and that the fullest expan- 

 sion and development of such life is possible only to animals that have 

 learned to draw on the vegetable kingdom for a large part of their 

 sustenance. Hence we are not surprised to find that in warm, arid 

 countries, where, during many months of the year, insect food is either 

 very scarce, or where the competition for food among ants and other 

 animals is very keen, a number of the former have become confirmed 

 vegetarians as their last resource in the struggle for existence. Under 

 such circumstances the seeds of herbaceous plants obviously furnish 

 the most accessible and nutritious food. The harvesting habit thus 

 developed is only one of many indications of an ever-increasing depen- 

 dence of ants on the vegetation, a subject which will occupy us in 

 several of the succeeding chapters. Even a few of the eminently ter- 

 restrial and carnivorous Ponerinse and Dorylinae, as we have seen, show 

 indications of vegetarianism. The three higher subfamilies, however, 

 have a much more varied and unstable diet, with an increasing ten- 

 dency to imbibe plant-juices, either directly from the floral and extra- 

 floral nectaries, or indirectly after they have passed through the bodies 

 of aphids and other Homoptera, or to feed on fungi, seeds or fruit. 

 Among these subfamilies certain tribes and genera have become so 

 addicted to specialized diets as to be of unusual interest. 



It is easy to conceive of the origin and development of the graniv- 



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