82 



liard chrysalis that had been painted over 

 seven years, and which was perfectly ahve. 

 A curious fact of an insect having been 

 found on planeing the surface of a writing 

 desk, in Guildhall, which had been used for 

 a great number of years, as is related in 

 the Trans. Lin. Soc. Lond. 1815, puts 

 the matter beyond a doubt, that these 

 creatures will live for a great length of 

 time without making their appearance. 

 What reason have we therefore to put 

 limits to the law^s of nature on this head, 

 or what reason have we to doubt of the 

 white bug which we now complain of, 

 iiaving lain in a dormant state for ages, 

 and having now again made its appear- 



We do not know for what reason one should only 

 be protected by a silken cord, whilst the other has 

 a nest of a much firmer texture. It is worthy ob- 

 Bcrvation however, that these kinds in general are 

 more scarce, and the caterpillars are usually 

 found only one or two at most together. 



There are some insects that are described by 

 naturalists as coming regularly once in certain 

 periods, one of these is the tettigonia septendecem, 

 so called because it is supposed to appear only once 

 in seventeen years. 



