30 



species of ecouomic importance are recorded on this card. In case 

 no specimens are seen I'ed the "Ace. No." column says: "See notes" 

 or "See letter." Thus this card forms a record of all material 

 secured upon any species of economic impoi'tance, and by referring 

 to it all accessions of that species can be found at a glance. 



In connection with these distribution maps are used similar maps 

 printed on thin tracing paper. On one of these is shown in dif- 

 ferent colors the approximate faunal areas of the State, on another 

 the average rainfall for different sections or the rainfall for a given 

 year, on another the average mean temperatures, etc. By superim- 

 posing one of these maps upon the distribution maps one can ascer- 

 tain very quickly whether the insect is confined to any faunal area 

 or is controlled by weather conditions, etc., so that it is only preva- 

 lent under certain conditions of rainfall, temiierature, or altitude, etc. 



The 5 by 8 card has been adopted, as it is a standard size and is the 

 largest size that can be carried in a cover in the pocket. For field 

 notes 5 by 8 heavy ledger paper, either with suitable heading or blank, 

 and punched for dui:>lex rod, is used. This is punched and carried in 

 a "price book," 7^ l)y 5, for sale by stationery dealers. A i)unch for 

 this purpose is bought with the cover. This cover is made of flexible 

 morocco and is the best note cover I have used, ]3ermitting the inser- 

 tion or removal of any sheet without disarranging the rest of the con- 

 tents. A stiff cover would not ijermit the use of 5 by 8 slips, as it 

 could not be carried in an oi-dinary pocket. When these note slijis 

 are removed they are at once filed in their proper place without copy- 

 ing. AVliere it is desirable, diagrams of arrangement of plots, or 

 schedules for i-ecording data can be made and a number of copies 

 made on these slips wath a duplicator, either for field or laboratory 

 use. I find this card large enough for almost all purposes of record, 

 and a 5 by 7 photo print (the largest commonly used) can be placed 

 on it. In many cases when a letter is received which is of such a 

 nature that it contains the information to be recorded in as concise a 

 way as if transcribed, it is folded once and one edge pasted on a card 

 and filed that way. If large blanks or schedules are necessary foi- any 

 purpose, they are folded so as to be slightly smaller than 5 by 8 and 

 one corner attached to a card. 



If now we were to undertake tlie study of sweet-potato insects, by 

 tui-ning to our food catalogue we have a list of all the species which 

 we have observed injuring that plant, with the accession number or 

 reference to notes or letter concerning each entry. If the sweet-potato 

 weevil is then to be studied, we would turn to experiment No. 17, 

 where would be found all the notes upon that species, with a record 

 of all accessions of it and parasites and predacious enemies on the 

 guide card. But where we wish to learn of some pest which has no 

 experiment number, we would refer to the systematic file. Here under 

 the i)roper family we would first find the double card bearing the dis- 



