312 



INSECT LIFE. 



specimens are ready to be put in a permanent place they are trans- 

 ferred to the wooden blocks ; after this it is seldom necessary to 

 remove the pins from the wood. 



Where the block system is used it is very important that the in- 

 sect cases be of uniform size, so that the blocks shall fit well. This 

 can be assured by having an iron frame over which each case is 

 fitted when made. The corners should be cut from this frame so 



as to make room for the glue that is pressed 

 out from the corners of the case by the clamps 

 that are used in making the case (Fig. 278). 



The blocks also should be of uniform sizes. 

 This is most easily attained where they are 

 cut by machinery, and, too, they are much 

 cheaper when made in this way. Those used 

 by the writer are made by a manufacturer 

 of bee-keepers' supplies, and cost unpainted 

 three dollars per thousand. 



The blocks are all one third inch in thick- 

 ness and 4||- inches in length. This admits 

 of there being four columns of blocks in each 

 case.* The variation in size is attained by having the blocks of 

 differing widths. There is given below a list of the widths ot blocks 

 used in the entomological collections under the charge of the writer. 



BLOCKS FOR MOUNTING INSECTS. 



FIG. 278. Iron frame 

 for mold for cases. 



The outside dimensions of the case are sixteen inches by nineteen 

 inches. As the wooden sides are half an inch thick, the case measures 



