222 



ANTS. 



of the walls and woodwork. According to Forel ( 1874), certain Euro- 

 pean ants ( Lasius emarginatus and others ) often nest in stone masonry. 

 In our Atlantic States l.cptothora.r longispinosus, which originally 

 nested under small stone> lying on boulders or in old nuts lying on the 

 ground, frequently nests between the stones of the rough stone walls 

 that enclose woods or pastures. 



Accessory Structures. Ant colonies do not always confine their 

 constructive activities to the nest in which they are rearing their brood, 

 but may extend their influence over the wider area on which they are 

 accustomed to seek their subsistence. Evidences of this influence are 

 -em in the great, bare clearings, sometimes 3-10 meters in diameter, 

 with which Pogonomyrmex occidcntalis, P. barbatns and its several 

 varieties surround their gravel cones or discs. In addition to these 

 clearings, P. barbatns also makes paths that radiate out into the sur- 

 rounding vegetation, sometimes to a distance of 20 to 30 meters. These 



FIG. 124. The spinning glands (sericteries) of ant larvae. (Karawaiew and 

 Doflein.; A, Larva of Polyrhachis untelleri ; B, of Lasius flatus ; C, of Tetramorium 

 cespitum ; D, of (Ecophylla smaragdina ; the spinning glands (sp) are most highly 

 developed in the two forms (A and D) which are used as shuttles in weaving the nest. 



are most beautifully developed on the high plateau not far from the 

 City of Mexico, where they are sometimes 10-20 cm. broad and re- 

 semble footpaths. More boreal species, like Formica pratcusis of 

 Europe and F. inte</ra of the United States, often make tenuous paths 

 which are roofed over along much of their extent with vegetable detri- 

 tus and connect the different nests of a colony with one another. 

 These and other species of Formica are also fond of constructing along 



