SAMOUELLE'S 



purpose it settles on a near object, a wall, or a tree, 

 and this second operation lasts longer than the first ; 

 sometimes it requires several hours, but in some 

 small species only a few minutes, to disengage the 

 insects from this last covering. A person standing 

 by a pond or brook, in a close evening, in the be- 

 ginning of June, will soon have his cloaths covered 

 with these exuviae. The creature being now the 

 perfect insect, hastes away to perform the remaining 

 function of its nature. The males fill the air for 

 a few hours after sun-set, and the females hover 

 upon the surface of the water to drop their eggs. 

 In this period of their existence, they take no nou- 

 rishment, and therefore soon die." 



Our much-esteemed and valuable friend, J. S. 

 Bowerbank, Esq. has made the following observa- 

 tion in the third number of the Entomological Mag. 

 which we copy, as they may be useful to the lover of 

 the microscope. 



"These larvae may be found in considerable num- 

 bers in small pools of water in boggy or marshy 

 places ; mine were procured from similar situations 

 on Hampstead Heath. They may be preserved for 

 many months in glass jars, or other vessels, with a 

 little duck-weed floating upon the surface of the 

 water. In selecting them for the purpose of exhibit- 

 ing the circulation of the blood, care should be 

 taken to choose such as have not yet attained a 

 greater length of body than about one-eighth of an 

 inch, as the whole insect may then be subjected to 

 examination, with a reasonable expectation of seeing 

 the full extent of the great dorsal vessel ; particularly 



