DONISTHORPEA. 205 



having traced out the plan of their masonry, in laying here and 

 there foundations for the pillars and the partitions they were about 

 to erect, they gave them more relief by adding fresh materials. It 

 often happened that two little walls, which were to form a gallery, 

 were raised opposite, and at a slight distance from each other. 

 When they had attained the height of four or five lines, the ants 

 busied themselves in covering in the space left between them by a 

 vaulted ceiling. Quitting, then, their labours in the upper part of 

 the building, as if they judged all their partitions of sufficient 

 elevation, they affixed to the interior and upper part of each wall, 

 fragments of moistened earth, in an almost horizontal direction, 

 and in such a way, as to form a ledge which, by extension, would 

 be made to join that coming from the opposite wall. These ledges 

 were about half a line in thickness ; and the breadth of the galleries 

 was, for the most part, about a quarter of an inch. Here several 

 vertical partitions were seen to form the scaffolding of a lodge, 

 which communicated with several corridors, by apertures formed 

 in the masonry ; there, a regularly formed hall, the vaulted ceiling 

 of which was sustained by numerous pillars ; further off might be 

 recognized the rudiments of one of those carrefours of which we 

 have before spoken, and in which several avenues terminate. These 

 parts of the ant-hill were the most spacious ; the ants, however, 

 did not appear embarrassed in constructing the ceiling to cover 

 them in, although they were often more than two inches in breadth. 

 In the upper part of the angles formed by the different walls they 

 laid the first foundations of this ceiling, and from the top of each 

 pillar, as from so many centres, a layer of earth, horizontal and 

 slightly convex, was carried forward to meet the several portions 

 coming from different points of the large public thoroughfare." 8 



Donisthorpea nigra feeds on a variety of substances, it kills and 

 devours flies and other small insects, etc., harbours numerous 

 subterranean Aphidae and Coccidae in its nests, and also visits 

 other species on plants and shrubs, sucks the nectar of flowers, 

 and collects seeds. 



Daniell records seeing nigra kill and drag off a wounded honey- 

 bee, and he observed thousands of these ants attending the scale 

 Coccus vitis L., on vines, and others collecting aphides on Calceo- 

 larias 13 . He seemed to think the ants killed these plant-lice, 

 because he saw them tearing off the wings of the latter, but ants are 

 known sometimes to remove the wings of these insects to prevent 

 them from escaping. " W.E.G." recorded the " garden ant " 

 milking some black aphides on broad beans in a garden at Bristol 35 , 

 and I have taken many species of Aphidae (and also Coccidae) in 

 numbers on subterranean roots, and at large, in nigra nests under 

 stones. Sich sent me specimens of this ant taken in his green- 

 house at Chiswick which were attending the scale Lecanium hesperi- 

 dum on ferns, and H. Miiller records finding the workers in the 



