SCIENTIFIC SURVEY. 



163 



the figure indicated. The ring should be of 

 brass, and the shallow net be made of grass- 

 cloth or coarse millinet. Small aquatic spe- 

 cies can be fished up in mud which will strain 

 through the net, leaving them to be picked 

 up and pinned. When the insect is taken in the bag-net by a 

 dexterous twist of the handle, which throws the bottom over the 

 mouth, it should be confined with the other hand with great care, 

 and then pinned through the thorax, when in the net. The pin 

 can be drawn through the meshes upon opening the net. The pin 

 should be thrust through the thorax so that three-fourths of it 

 should be below the insect ; care should be taken to preserve some 

 uniformity of height from the cork in the different specimens. 

 After being pinned the specimen should be handled with a pair of 

 curved pincers, whose jaws should be roughened to retain the pin, 

 and kept apart by their opposite ends being united, as in the sur- 

 geon's dissecting forceps ; or the handles may be large, and a spec- 

 ial spring introduced between to keep the branches apart. These 

 pincers are indispensable in handling specimens, especially those 

 on slender pins. 



Some specimens should be preserved as they look when at rest. 

 To set specimens a number of selling-boards will be necessary. These 

 should be made of soft wood, with grooves or cracks of different 

 sizes, in the bottom of which strips of cork, or corn-stalk, or paste- 

 board should be fastened, into which the insect's body can be re- 

 ceived, while the pins stick through beneath. The surface of the 

 board should incline a little towards the groove, as the wings often 

 fall down a little after the specimen is dry. The wings can be 

 arranged with a needle stuck into a handle of wood, the wings set 

 horizontally, and the front margin of the primaries drawn a little 

 forward of a line perpendicular to the body, so as to free the inner 

 margin of the secondaries from the abdomen, that their form may 

 be clearly seen, as in the figure (11.) When thus arranged they 

 can be confined by pieces of card, as indi- 

 cated, or by square pieces of glass laid % 

 upon them. Several days are requisite for 

 them to dry thoroughly. Several of these 

 setting-boards can be made to slide into a 

 frame covered with gauze-wire, to keep 

 them from devouring insects, while the air 

 may at the same time have constant access to them. 



Fig. 11. 



