Miscellaneous. 91 



extent may sometimes be very considerable. We may note by the 

 way that, at the end of summer, the ground is covered at a great dis- 

 tance from the entrance with a heap, often considerable, of glumes and 

 empty capsules continually brought from the interior, where the 

 seeds alone are preserved. 



The nature of the soil in which ant-hills are found renders very 

 difficult the observation of what takes place within. Mr. Moggridge, 

 desiring much to know the end of the history of these seeds, which he 

 saw enter in so large a quantity, was not discouraged, and at last 

 found an ant-hill which, being parallel to the wall of a terrace, could be 

 with sufficient facility explored throughout. Following the galleries, 

 he ascertained that the seeds (which belonged to more than eighteen 

 families of plants) were carefully accumulated in little cavities or 

 granaries, the size of which varies between that of a watch and that 

 of the palm of the hand. These have a floor carefully made with 

 small grains of mica and quartz cemented together ; the upper part 

 has in general the form of a vault. He proved moreover the curious 

 fact that the seeds found in these granaries scarcely ever (hardly 

 one in some thousands) present a commencement of germination, 

 although they are often in conditions of humidity, depth, and tem- 

 perature very favourable to their development. How can the ants 

 obtain this result ? This problem of vegetable physiology has not 

 yet been solved ; but Mr. Moggridge has been able to convince him- 

 self that it was absolutely necessary, in order that germination 

 should be arrested, that the ants should be able to visit the granaries. 

 If the visits are interrupted, then germination commences immedi- 

 ately. Mr. Moggiidge asked himself if formic acid might not be 

 the cause of the suspension of germination ; but his recent experi- 

 ments do not permit him to conclude so. 



When, in consequence of certain circumstances, a seed in one of 

 the granaries sprouts, as soon as the radicle has attained a certain 

 length it is cut at its free extremity by the ants ; the seed is then 

 taken out of the nest, exposed to the sun, then brought back to the 

 interior and devoured with avidity, as at that time it contains a sac- 

 charine substance. 



Different colonies of Atta harham often wage fierce war for the 

 possession of their provisions ; and Mr. Moggridge has followed the 

 various phases of a struggle between two swarms, which lasted 46 

 days (from the 18th January to the 4th of March). It appears that, 

 in fighting, the ants mostly try to seize one another by the antennae ; 

 and when one of them has been thus laid hold of, it immediately 

 loses all energy. Some of the ants appear to be specially charged 

 with the office of plunder ; for, on several occasions, Mr. Moggridge 

 observed that the ants which returned loaded with booty delivered 

 it at the entrance of their dwelling to other workers, and set off 

 again immediately. 



Although Atta harhara and A. structor spend most of their time 

 in gathering seeds, they also pursue small insects, which they either 

 devour at once or carry into their habitations. 



Having installed a colony of Atta harhara, with their queen and 



