334 SUMMARY or CUBRENT RESEARCHES RELATING TO 



the previous evening. " The manner of opening the gate cannot be 

 fully described, because the work is chiefly done within and behind 

 the outer door of gravel. The mode would doubtless be correctly 

 indicated by reversing the process of closing gates presently described. 

 "What I saw was, first, the appearance of the quivering pair of an- 

 tennas above one of the pebbles, followed quickly by the brown head 

 and feet projected through the interstices or joints of the contingent 

 gravel-stones. Then forth issues a single worker, who peeps to this 

 side and that, and after compassing a little circuit round about the 

 gate, or perhaps without further ceremony, seizes a pebble, bears it 

 oflf, deposits it a few inches from the gate, and returns to repeat the 

 task ; she is followed sometimes cautiously and at intervals of ten, 

 twenty, even thirty minutes, by a few other ants, who aid in clearing 

 away the barricade, after which the general exit occurs. Again 

 there is a rush of workers almost immediately after the first break, 

 who usually spread over the hill, bristling around the gate, gradually 

 widening the circles, and finally push out into the surrounding 

 herbage. At first the exit hole is the size of a pea, perfectly round, 

 and plainly shows that sand and soil have been used under the gravel 

 to seal up the gate. The whole appeared to have been cemented, 

 probably by the moisture of the night dew. 



" The process of closing the gates is even more interesting to the 

 observer than the opening, as the various steps are more under his 

 notice. . . . At nest A the closing was chiefly from within. The 

 workers jmshed the sand from the inside outwards with their heads. 

 A grass straw about an inch long was brought from the interior and 

 pushed out until it lay across the gate as a stay for the filling 

 material. Soil was here principally used for closing, a few pebbles 

 being added." In another case, " when the gate was nearly closed a 

 straggling minor came back from the commons and essayed entrance, 

 wherein she failed. Several trials and failures succeeded, whereupon 

 she commenced dragging the dirt from the opening. While thus 

 engaged the major approached with a huge bit of gravel, which she 

 deposited on her comrade with as much nonchalance as though she 

 were one of the adjoining pebbles. At last the minor dug out a 

 tiny hole through which she squeezed into the nest, and the major, 

 who was deliberately approaching close behind her, carrying another 

 pebble, immediately sealed up the opening. During this amusing 

 episode the straggler made no effort to aid in the closing, being 

 wholly intent on entering, and the gate-closer paid no attention 

 to her whatever, beyond the first sudden and satisfactory antennal 

 challenge. Each moved forward to her own duty with the undisturbed 

 plasticity of a machine." 



This " by-play " between the gate-closers and the late-returning 

 foragers is not the exception but the rule ; nevertheless it does not 

 appear that the foragers ever so far miscalculate their time as to 

 arrive after the gates are completely closed. When the gates are all 

 but closed there is generally but a single ant engaged in the closing 

 process from without ; this ant slips in at the last moment, and the 

 process is finally concluded from within. The gates are similarly 



