TRAYS AND TEST-TUBES. 81 



in little pasteboard trays, each holding a set, and con- 

 taining a paper label on which various items that 

 cannot be traced on the shell are written in full. 

 The trays may then be classified in the shallow 

 drawers. 



"Such trays should all be of the same depth, — half 

 an inch is a convenient depth for general purposes ; 

 and of assorted sizes, say from one inch by one and 

 and one-half up to three hy six inches ; it is conve- 

 nient to have the dimensions regularly graduated by 

 a constant factor of, say half an inch, so that the 

 little boxes may be set side by side, either lengthwise 

 or crosswise, without interference." They may be 

 made to order, without much cost, by any box man- 

 ufacturer ; or a druggist will sell to you boxes used 

 in his business which are highly suitable. 



I think we may borrow a hint from the concholo- 

 gists in the case of small and rare specimens, which 

 we want to show freely, and yet regard as almost too 

 precious to be looked at with one's eyes wide open. 

 I refer to the use of stout, short test-tubes of glass, 

 of a size suitable to the egg. These are made for 

 the use of chemists and can be bought by the dozen ; 

 or, tubes of glass can be bought and cut by yourself 

 into suitable lengths. A whole suite of any of the 

 smaller eggs can be inserted one by one in the same 

 tube, each egg separated from its fellow and ren- 



