THE HERDS OF THE YELLOW ANT. 



77 



little creatures and appear to be paying them some kind of court. 

 When I cut the vine for photographic purposes, six or eight ants 

 were standing about the large individual mentioned above ; they soon 

 became aware that some dire calamity had happened, or was about to 

 happen, either to their beloved herd or to themselves, and, becoming 

 frightened, soon abandoned cattle and pasture and fled away in panic 

 terror. I had hoped to photograph them in situ, but found this to 

 be impossible with the instruments at my disposal. 



The ants do not " milk " these white aphides, neither do they 

 eat the excrementitious substance on their backs. The white indi- 

 viduals, however, seem to be factors in the social economy of the 

 herd, for the ants move them, on occasions, along with the herd to 

 other pastures. Once I saw an ant pick up a white aphis and 

 carry it to a leaf some little distance away from the colony; she 

 then returned, picked up a gravid nectar-producing aphis, and car- 

 ried her to the spot where she had left the white individual. In 

 a few days a fine herd of " milkers " was to be seen grazing in the 

 new field. I judge from this that these white aphides are in some 

 way useful to, if not absolutely necessary for, the welfare of the 

 herd. 



The winged females have both compound eyes and ocelli, or 

 primitive eyes, yet they seek the under surface of the leaf, thus 

 seeming to prefer the more subdued 

 light to be found there. The young are 

 always deposited on the under surface 

 of the leaves; in a few days, however, 

 they either migrate of their own accord 

 to the more succulent stems or are car- 

 ried thither by the ants, which never 

 cease to watch over and care for them. 



In order to test this guardianship, 

 I have frequently wounded the vine be- 

 low a colony of aphides, thus cutting 

 off, to a certain extent, the flow of sap. 

 The ants would soon discover this and 

 would at once begin to move the -herd 

 to another vine. The aphis is pro- 

 vided with boring and suction organs 

 somewhat similar to those of the mos- 

 quito. In point of fact, it is interesting to note that the ances- 

 tors of the mosquito, in all probability, lived wholly on the juices of 

 plants; hence, in this respect, the resemblance is more real than 

 apparent. Aphides, also, like mosquitoes, have the curious habit 

 of elevating their bodies, " standing on their heads," after they 



An Aphis-Lion. 



