30 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



may be of interest. The negatives when filed are numbered con- 

 secutively and catalogued in a book in the same sequence. After 

 several negatives of a subject had been made, it was often necessary 

 to examine a number of negatives to find the one desired. A card 

 index is used to supplement the book catalogue. A print from each 

 negative is mounted on a regular 5x8 index card. The subject and 

 number of the negative is placed at the top and the cards are arranged 

 alphabetically. The prints used are often some that are not suitable 

 for halftones and are attached to the cards with binding strips or a 

 non-curling gelatine mountant. Prints from two or more different 

 negatives of the same subject are often mounted on the same card. 

 This index has proven very convenient and saves much time in looking 

 up negatives. 



Thus with the simple apparatus and devices described, photographs 

 up to ten diameters, prints, enlargements of any reasonable size 

 and lantern sHdes can be quickly and conveniently made. This 

 occupies less than seven square feet of space and could be duplicated 

 for between $100 and $120. 



Vice-President G. A. Dean: The paper is now open for dis- 

 cussion. 



Mr. G. W. Herrick: I would like to ask if Mr. Walden has any 

 trouble with shadows when he places his specimens on a horizontal 

 shelf. 



Mr. B. H. Walden: The specimens are placed on a sheet of ground 

 glass. Many workers use plate glass, but we prefer the ground glass 

 and if the background is placed a proper distance below, we have very 

 little trouble with shadows. 



Mr. W. C. O'Kane: Mr. Walden's statement with regard to a 

 field camera with high grade lens is interesting. I should like to ask 

 if he has had experience with supplemental lenses added to an ordinary 

 lens thereby avoiding long focus bellows, because our experience with 

 long focus has not been pleasant. I have not had any experience with 

 supplementary lenses but should like to know about it. 



Mr. B. H. Walden: I have never used a supplementary lens for 

 this work, but have seen one used in connection with other work and 

 the results were not entirely satisfactory. 



Vice-President G. A. Dean: We will now listen to a paper by 

 Dr. T. J. Headlee. 



