264 INSECT SOCIOLOGY 



the edges of leaves. Having no means of their own of 

 fastening the structure, these ants have recourse to their 

 own larvae, which have glands secreting a mucilage for 

 the formation of a cocoon. Drawing the edges of the 

 leaves together, the ants pass the larvae (small white 

 grubs) to and fro along the two surfaces, which presently 

 are glued together by the thread of soft silk proceeding 

 from the spinners of the larvae. 



XL VIII 



The civilised organisation of ants and bees is an endless 

 insect source of wonder-stirring manifestation. Lord 

 sociology Avebury and others have explained their per- 

 fect co-operation, their respect for authority, their habits 

 of slave-keeping and tending herds of aphides ; but, per- 

 haps, it is not so commonly known that one species of 

 American ant live by an elaborate system of horticulture. 

 These leaf-cutting or parasol ants are so called from their 

 spending their time in running about with circular pieces 

 cut from the leaves of trees. Often the nest is at a con- 

 siderable distance from the tree. Mr. M'Cook describes 

 one instance where a passage ran from the nest about 

 eighteen inches underground for 448 feet, and then above- 

 ground for 185 feet to the tree, the whole course being 

 almost in a straight line. Nobody knew why such masses 

 of leaves were stuffed into the nest, until Alfred Moller 

 discovered that the harvesters pass the crop into the hands 

 of a specialised gang of workers which remain within the 

 nest. These, having cut up and masticated the leaf frag- 

 ments, store them in heaps and wait till a slender fungus 

 spreads through the mass. This fungus they treat in a 



