16 



clay, rather compact, and well formed to retain any impression it 

 might receive; and as the holes are always filled below with earth 

 removed from above, through their whole course, their depth was 

 easily ascertained. They were uniformly found filled to within 

 six or eight inches of the top, with earth from which all vegetable 

 matter had been extracted, and packed so hard that their depth 

 could not be mistaken. In no case could we trace them to the 

 blue stratum of clay below. From this fact it is clear that this is 

 the utmost depth of their domicil in the latter stage of their sub- 

 terraneous pilgrimage. All that seems to be required for the safety 

 of the insect under ground is a temperature congenial to its degree 

 of vitality; and although they descend deeper in search of ali- 

 ment, previous to the assumption of the pupa state, it is clear there 

 can be no necessity for it after it. The late Mr. William Patter- 

 son, of this city, saw them three feet below the surface of the 

 earth, when they were very small, not quite three years old. The 

 extent of the descent in this state is also confirmed by inspecting the 

 bottom of their chambers, where we always find a certain quantity 

 of refuse matter, hard and compact, in the form of a plug. This is 

 neither of the consistence or colour of the surrounding soil, but fecal 

 matter, strongly cemented, stiffer and more clay-like. It would ap- 

 pear, from these facts and reasoning, as a consequence, that the ob- 

 jection so often made to Jihe superficial descent of the locust is 

 futile. It has been remarked that the ground, during our cold win- 

 ters, sometimes freezes below the depth of eight or ten inches. Before 

 the chambers are constructed, they can descend as low as their in- 

 stinct directs them to be agreeable, and certainly do, as we never 

 find any diminution of numbers at any ascension after the hardest 

 winters. If we examine the construction of the chambers which 

 seem to be intended to protect them, in their most tender state, we 

 find them ample and admirably formed for that purpose. The walls 

 are thick and strong, cemented so firmly that water will not pene- 

 trate them, nor heat easily escape, preserving nearly a uniform 

 temperature. 



The superficial descent of the locust, and the construction of its 



