ENTOMOLOGICAL NEWS. 



[The Conductors of Entomological News solicit and will thankfully receive items 

 of news likely to interest its readers from any source. The author's name will be given 

 in each case, for the information of cataloguers and bibliographers.] 



To Contributors. — All contributions will be considered and passed upon at our 

 earliest convenience, and, as far as may be, will be published according to dale of recep- 

 tion. Entomological Nkws has reached a circulation, both in numbers and circumfer- 

 ence, as to make it necessary to put " copy " into the hands of the printer, for each num- 

 ber, three weeks before date of issue. This should be remembered in sending special or 

 important matter for a certain issue. Twenty-five " extras," without change in form, 

 will be given free, when they are wanted ; and this should be so stated on the MS., along 

 with the number desired. The receipt of all papers will be acknowledged. — Ed. 



Philadelphia, Pa., April, 1900. 



In January, 1891, through the kindness of Mr. Julius F. 

 Sachse, a well-known scientific and literary gentlemen of this 

 city, we published a half-tone of the larva of Citheronia regalis. 

 As far as we know this was the first time that this process of 

 photography had ever been used in a natural history journal. 

 Since then the use of half-tones for illustrative purposes has 

 become general. In December, 1891, we also published "A 

 Suggestion for a Possible Method of Identifying the Colors 

 Photographed." This work was also done by Mr. Sachse and 

 was a step in advance. Since 1891 photographic processes 

 have been improved in various ways, and in this number we 

 give illustrations of the so-called three-color process. Three 

 negatives of the objects are made, each one through a different 

 "color screen," respectively, red, yellow and blue. Three 

 half-tones are then made from these negatives, and then by 

 making an impression on the pajx;r from each half-tone block, 

 and using for each block one of the three inks — yellow, red 

 blue — the ixrrfect print is obtained. Great care must be taken 

 in regi.stering the blocks, so that each color shall proj^erly 

 cover the figures. The process is a wonderful one and is 

 beautifully adapted for natural history work, as it gives me- 

 chanically correct maculation and is ])ractically correct for 

 color. This is our first plate of the kind, and was made here 

 in Philadelphia. 



