294 
NATURAL HISTORY. 
heaped upon each other four deep ; in others, they covered 
the surface like a black cloth : the trees bent beneath their 
weight; and the damage which the country sustained ex- 
ceeded computation. In Barbary their numbers are formida- 
ble, and their visits are frequent. In the year 1724, Dr. Shaw 
was a witness in that country of their devastations. Their 
first appearance was about the latter end of March, when the 
wind had been southerly for some time. In the beginning of 
April, their numbers were so vastly increased, that, in the heat 
of the day, they formed themselves into large swarms, which 
appeared like clouds, and darkened the sun. In the middle 
of May, they began to disappear, retiring into the plains to 
deposit their eggs. In the next month, being June, the 
young brood began to make their appearance, forming many 
compact bodies of several hundred yards square; which af- 
terwards marching forward, climbed the trees, walls, and 
houses, eating every thing that was green in their way. The 
inhabitants, to stop their progress, laid trenches ell over their 
fields and gardens, filling them with water. Some placed 
large quantities of heath, stubble, and such like combustible 
matter, in rows, and set them on fire, on the approach of the 
locusts ; but all this was to no purpose ; for the trenches 
were quickly filled up, and the fires put out by the vast num- 
ber of swarms that succeeded each other. A day or two after 
one of these was in motion, others that were just hatched 
came to glean after them, gnawing olF the young branches, 
and the very bark of the trees. Having lived near a month 
in this manner, they arrived at their lull growth, and threw 
off their worm-like state, by casting their skins. To prepare 
themselves for this change, they fixed their hinder feet to 
some bush or twig, or corner of a stone, when immediately, 
by an undulating motion used on this occasion, their heads 
would first appear, and soon after the rest of their bodies. 
The whole transformation was performed in seven or eight 
minutes’ time ; after which, they were a little while in a lan- 
guishing condition: but as soon as the sun and air had 
hardened their wings, and dried up the moisture that remained 
after casting of their sloughs, they returned again to their 
former greediness, with an addition both of strength and 
agility. But they did not continue long in this state before 
they were entirely dispersed ; after laying their eggs, di- 
recting their course northward, and probably perished in the 
sea. It is said, that the holes these animals make, to deposit 
their eggs, are four feet deep in the ground; the eggs are 
about fourscore in number, of the size of carraway comfits, 
and bundled up together in clusters. 
