174 ZOOLOGY. 



Farn 14. Mutillidcß. This family approaches the Formicidm (ants) in 

 general appearance, but the species are solitary, and provided with a long 

 curved sting which can be used very effectually, on account of the flexi- 

 bility of the abdomen. There are but two kinds of individuals, male and 

 female, the latter being apterous. The species inhabit hot and sandy 

 localities, and they are often covered with short hair, sometimes vividly 

 colored with red, yellow, and black. Mutilla {jpl. 1%^fig. 1), Apterogyna 



fig- 2). 



Fam. 15. Formiddce (jy^. 79, figs. 3-9). This is the family of the 

 ants, in which the head is triangular, the antennie filiform, and elbowed at 

 the end of the basal articulation, the mandibles robust, the abdomen oval 

 and attached by a narrow pedicle, and the feet slender and cursorial. 

 These insects live in society in burrows of their own construction, which 

 are found in the earth, or in dead trunks of trees. Some form a rough hill 

 out of clay mixed with bits of vegetable material. Formica mei'dicola^ of 

 Brazil, builds a nest of dry horse excrement, upon the stems of reeds and 

 trunks of trees. A somewhat similar nest (figured in Kirby's Bridgewater 

 Treatise) is constructed upon the branches of trees by Myrmica hwhii. 



The Brazilian Formica elata of Dr. Lund makes a nest upon the trunks 

 of trees out of clay and leaves. A minute species of the United States, 

 which seems to be Myrmica domestica^ is found in small colonies under 

 stones, but it occasionalh' takes up its residence in old galls upon oak shrubs, 

 entering by the aperture made by the retiring Cynips^ and adapting the 

 interior to its purpose. The same species swarms in some houses, both in 

 America and England. 



x\. few individuals like workers, but with a very large head, are sometimes 

 found. Among the driver ants of Western Africa, according to the obser- 

 vation of Dr. T. S. Savage, there are three or four kinds : neuters^ soldiers., 

 workers, and carriers. 



Besides the ordinary males and females, which are not numerous, the 

 societies of ants are made up chiefly of workers, sometimes named neuters, 

 which are abortive fenudes without wings, of a smaller size and more indus- 

 trious habits than the others. These have all the work of the establishment 

 to perform, whether in building, collecting food, or taking care of the eggs 

 and young. The difference between a worker and a female is probably due 

 to a peculiar mode of feeding, as with the bees, where the larva, if a worker, 

 is transformed into a queen when accident deprives the hive of the latter. 

 The male and female are winged, but the wings are dropped after a certain 

 time, and the latter is larger than the former. 



In cold climates the male and female ants die in winter, and the neuters 

 remain torpid, so that they do not require a stock of food. But under other 

 circumstances a store of food is collected. Thus an East Indian species 

 collects a great quantity of grass-seed, which is brought to the surface to 

 dry after the heavy rains of that country. Ants are fond of the liquid 

 matter exuded by the Aphides., and they frequent the trees where they are 

 found, for the purpose of getting it ; and by annoying the Aphis they can 

 cause it to furnish a globule. Certain species of Memhracis are treated 

 378 



