10 



tenuity of the exhalation from tender vegetable barks is such, that 

 the imagination can scarcely paint, and never could dream of it, 

 without the finest glasses. If it were possible, it might bear some 

 faint resemblance to the fracture of a diamond of the first water, 

 bespangled into myriads of chrystals! 



There are two varieties of the decem septima, but only as to size 

 or magnitude. The minor tribe constitutes about, a hundredth part 

 of the whole race. We find the smaller at the same time and in 

 the same places with the larger variety, and all their organs and 

 habits the same. As we very seldom find any of an intermediate 

 size, it may be a question whether there is any sexual intercourse 

 between them ? The negative would seem to argue the violation of 

 a law of nature. They are about seven eighths of an inch long, 

 and five tenths in diameter. 



Although the locust has received its distinctive appellation from 

 tbe singularity of its appearance once in seventeen years, and uni- 

 form experience confirms it, there, are still some who fancy they 

 have found exceptions to this law of nature. The want of obser- 

 vation, and too much credulity in popular rumour, has led them 

 into this error. 



They do not appear at the same time over the whole area of 

 their nativity, but cover the whole ground by the same family once 

 in seventeen years, comprising others that sometimes intervene, 

 both having inhabited the same grounds since they were created. 

 Although all the families are uniform in their ascension, in time and 

 place, there may be two generations in the same place oftener than 

 once in seventeen years, because they were so located originally. 

 Such occurrences have confounded and deceived many, and made 

 them sceptics. Some examples within our own observation (and 

 we could adduce many more) will solve the problem. A part of 

 Virginia and Maryland will be sufficient. Here two families occu- 

 py the same grounds on each side of the Potomac river a part of 

 Loudon county on the South, and a part of Montgomery on the 

 north, or Maryland side, compose one section, while Fauquier 

 county, in Virginia, that lies adjacent to Loudon, form part of ano- 



