354 THE UNIVERSE. 



of these Neuroptera undertake a distant journey, they 

 advance in a straight line, and all the workers march in 

 columns of ten to fifteen individuals, as compactly as a 

 flock of sheep. During this time the termites that are 

 armed with strong mandibles, and play the part of sol- 

 diers, spread themselves out like reconnoitrers on each 

 side of the phalanx, in order to guard it against every 

 attack. Should a plant more elevated than the others lie 

 in the way of the emigrants, the soldiers may be seen 

 climbing to the highest leaves, and resting suspended there 

 like so many sentries charged with the office of watching 

 the route. Should any danger arise, these soldiers, by 

 striking the leaves with their feet, produce a clicking 

 noise; a signal that agitates the entire army, which replies 

 by hissing, and immediately after redoubles its pace with 

 fresh ardour. 



In juxtaposition with these emigrating insects, we ought 

 to mention those which, withovit executing adventurous 

 journeys, suddenly appear in compact masses and become 

 for a time the scourge of our fields. 



One of these voi^acious depredators is the may-bug, so 

 common in France. In his magnificent Avork on the ene- 

 mies of woodland culture, M. Katzel)urg does not hesitate 

 to represent it as the most terriUe destroiier of our planta- 

 tions. The annals of agriculture abound Avitli aftiicting 

 details of the ravages caused by this insect. It is some- 

 times seen to devour in a very short time all the foliage 

 of a vast extent of forest. I was enabled to observe one 

 of these devastations in a wood in the department of the 

 Seine-Inferieure. All the trees had been utterly despoiled 

 of their verdure; not a leaf, strictly speaking, hung on one 

 of tliem; and in this forest, Avhich we traversed in the 

 middle of summer, we might have thought ourselves in 



