IMPERFECT SOCIETIES OF INSECTS. 15 
plants and shrubs. Shortly after the whole body begins 
to move forward in one direction and with little deviation. 
They resemble a swarm of ants, all taking the same 
course, at small distances, but without touching each 
other: they uniformly travel towards a certain region as 
fast as a fly can run, and without leaping, unless pursued ; 
in which case, indeed, they disperse, but soon collect 
again and follow their former route. In this manner 
they advance from morning to evening without halting, 
frequently at the rate of a hundred fathoms and upwards 
in the course of a day. Although they prefer marching 
along high roads, footpaths, or open tracts; yet when 
their progress is opposed by bushes, hedges, and ditches, 
they penetrate through them: their way can only be im- 
peded by the waters of brooks or canals, as they are ap- 
parently terrified at every kind of moisture. Often, how- 
ever, they endeavonr to gain the opposite bank with the 
aid of overhanging boughs; and if the stalks of plants or 
shrubs be laid across the water, they pass in close columns 
over these temporary bridges ; on which they even seem to 
rest and enjoy the refreshing coolness. ‘Towards sun- 
set the whole swarm gradually collect in parties, and 
creep up the plants, or encamp on slight emimences. On 
cold, cloudy, or rainy days they do not travel—As soon 
as they acquire wings they progressively disperse, but still 
fly about in large swarms?.” 
‘In the month of May, when the ovaries of these in- 
sects were ripe and turgid,” says Dr. Shaw, “ each 
of these swarms began gradually to disappear, and re- 
tired into the Mettijiah, and other adjacent plains, where 
* Pallas, ii. 422-6. b Travels, 187. 
