PERFECT SOCIETIES OF INSECTS. 317 
observe the troop defile before them; traversing its ranks ; hastening to 
any point where their presence seems necessary, especially if it have met 
with any obstacle on its route ; and even climbing, as M. Lacordaire has 
often witnessed, up the adjoining plants, and perched on the margin of a 
leaf, surveying its passage from this elevated position.! M. Lund observed 
four of these large-headed neuters of a Brazilian species of Myrmica to 
guard the entrance to their nest, and others attending the column while on 
march, and hastening to the spot and alarming their comrades when some 
of the ants were purposely killed.* 
An equally singular modification of form and function takes place in the 
neuters of a Mexican ant— Myrmecocystus Mexicanus of M. Wesmael, 
who has described their economy in a paper read to the Académie Royale 
of Brussels. Of this species, while some of the neuters have the ordinary 
form, others, which never quit the nest and are almost inactive, have their 
abdomen swollen into an immense subdiaphanous sphere, filled by a kind 
of honey which they are solely occupied in elaborating, and which they 
subsequently discharge into cells analogous to those of bees.$ 
Having introduced you to the individuals of which the associations of 
ants consist, I shall now advert to the principal events of their history, re- 
lating first the fates of the males and females. In the warm days that occur 
from the end of July to the beginning of September, and sometimes later, 
the habitations of the various species of ants may be seen to swarm with 
winged insects, which are the males and females preparing to quit for ever 
the scene of their nativity and education. Every thing is in motion ; and 
the silver wings, contrasted with the jet bodies which compose the animated 
mass, add a degree of splendour to the interesting scene. The bustle in- 
creases, till at length the males rise, as it were by a general impulse, into 
the air, and the females accompany them. The whole swarm alternately 
rises and falls with a slow movement to the height of about ten feet, the 
males flying obliquely with a rapid zigzag motion, and the females, though 
they follow the general movement of the column, appearing suspended in 
the air, like balloons, seemingly with no individual motion, and having their 
heads turned towards the wind. 
Sometimes the swarms of a whole district unite their infinite myriads, 
and, seen at a distance, produce an effect resembling the flashing of an 
aurora-borealis. Rising with incredible velocity in distinct columns, they 
soar aboye the clouds. Each column looks like a kind of slender net-work, 
and has a tremulous undulating motion, which has been observed to be 
produced by the regular alternate rising and falling just alluded to, The 
Noise emitted by myriads and myriads of these creatures does not exceed 
the hum ofa single wasp. The slightest zephyr disperses them ; and if in 
their progress they chance to be over your head, if you walk slowly on 
they will accompany you, and regulate their motions by yours. The females 
continue sailing majestically in the centre of these numberless males, who 
are all candidates for their favour, each till some fortunate lover darts upon 
her, and, as the Roman youth did the Sabine virgins, drags his bride from 
the sportive crowd, and the nuptials are consummated in mid-air ; thong 
Sometimes the union takes place on the summit of plants, but rarely in the 
1 Lacordaire, Introd. & ?Entom, ii. 498. 
2 Lund in Ann, des Sciences Nat. xxiii. 118.; quoted by Lacordaire, ubi supr., and 
Westwood, Mod. Class. ii, 225. 
° Bull, Acad, Roy. Bruzell. v.771.; quoted by Westwood, ubi supr. ii, 225. 
