302 ENTOMOLOGY. 



but for permanent preservation he mounts them in a neat 

 and very useful cell devised by Dr. T. Taylor, which is 

 easily made of common beeswax, and can quickly be built 

 up to any desired height. " To make the cell harder, and to 

 raise the melting-point, a slight amount of powdered resin 

 is added. Both materials are heated together in a small 

 porcelain dish, so as to thoroughly combine them into a 

 homogeneous mass. If required for use, the dish is simply 

 heated, and the cell is made in the usual way upon a turn- 

 table. Since both turn-table and slide are colder than the 

 wax, the cell becomes visible at once, and, by repeated 

 applications with the brush, it can be made of any required 

 depth. If too high, or if too sloping towards the centre, 

 the wax can be readily removed upon the turn-table by the 

 application of a knife; a groove for the reception of the 

 cover-glass is also very readily made. The cell is now ready 

 for most purposes, and is an excellent one for mounting 

 with glycerine jelly and Canada balsam. If another ma- 

 terial oil, for instance is to be used which would dissolve 

 the wax, the inside of the cell should first be coated with 

 any of the usual varnishes, such as Brunswick black. The 

 same varnish should also be used from the outside to seal 

 the completed and filled cell. I have found such cells of 

 great utility in enclosing aquatic larvae. To do so satisfac- 

 torily, I make with a knife a shallow cut across the cell, 

 and fill the latter with water in which the larva to be pre- 

 served has been placed. By gently pressing down with a 

 cover-glass, I can secure the still living specimen in any 

 desired position. Now I remove with a piece of blotting- 

 paper a very small quantity of the water through one of the 

 cuts previously made, and allow at the other cut the pyro- 

 ligneous acid to enter. As soon as this acid has reached the 

 larva, this dies at once in the position occupied at the time. 

 The cell is now sealed in the usual way; but previous to 

 doing so the sides of the two cuts are pressed together. 

 " Specimens thus treated remain unchanged for a long 



