ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



733 



between three slips of cardboard, the upper and lower punched with a 

 circular hole (fig. 82), and the middle cut to the shape of the larger 

 cover-glass (fig. 83). They can be gummed together and placed in a 

 press and permanently sealed by means of spirit varnish. 



Dry and spirit-preserved insects must be soaked in water for a few 

 hours before dissection. 



Insects not larger than the common house-fly may be mounted 



Lower and upper piece. 

 Fig. 82. 



Middle piece. 



Fig. 83. 



whole without pressure. The initiatory stages are the same as the fore- 

 going, but instead of being placed on a slip the insect is placed in a 

 saucer on its back, and a little water poured in. After arranging in the 

 desired position the water is replaced by spirit. When the insect is 

 quite stiff, it is removed on a section-lifter to spirit in a closed flat- 

 bottomed vessel. When thoroughly dehydrated it is removed to turpen- 

 tine, and after 48 hours or so it is transferred to a slide and covered 

 with balsam. Place round 3 or 4 glass beads or a glass ring which have 

 been washed in alcohol and kept in turpentine. The cover- glass may 

 now be put on and weighted down with a bit of lead. Run in more 

 balsam and keep on doing so daily as the xylol evaporates. 



This preparation is best suited for the binocular Microscope and low- 

 power objectives ; the position of the internal organs can be well seen in 

 a successful preparation. 



Dec. 19th, 1906 



3 c 



