10 Bailey, Herbarium of British and Foreign Plants. 



assigned to such number or letter. If the sign is not underlined it- 

 means that there are specimens from i or 2 localities, or gathering's; 

 if underlined once — 3 to 5 localities; if underlined twice, 6 to S locali- 

 ties; if underlined thrice, g to 11 localities; and so on. 



These sections are by no means of equal area; in fixing 

 their boundaries regard was had to the relative frequency with 

 which plants from these areas would be likely to be available. 

 Thus, nearly the whole of European Russia and Siberia is 

 represented by a single number (17), whilst Germany and 

 Austria, to which numbers 18, 19, and 20 are assigned were, 

 from the greater accessibility of the plants therefrom, subse- 

 quently broken up into smaller areas; Western Germany (18) 

 into six divisions (A to F) ; Eastern Germany (19) into eight 

 (G to N) ; and portions of Austria (20) into five (O to S). It 

 would have been more symmetrical to have re-numbered the 

 areas from 18 onwards, but so much use had been made of them, 

 as originally planned, as to render it undesirable to change 

 them, and it is immaterial whether letters or numbers are 

 adopted, as they are merely symbols of the areas represented 

 in the herbarium. 



In the index each of these 43 geographical areas has a 

 separate column assigned to it, the columns being distinguished 

 from each other by coloured ruled lines. When the herbarium 

 contains a plant from any of the allotted areas, its presence 

 is indicated by the symbol assigned to it, every symbol being 

 entered under its own column in the index. If there are three 

 sheets of examples from the same area, its symbol is under- 

 lined once; when there are from four to six sheets from the 

 same area, it is underlined twice, and so on, each underline 

 representing three sheets. 



When an index of species has been made, it is used in two 

 sizes; in one the page measures 8 x 5|- inches, in the other 

 12 X 10 inches, according to the length of the index, the octavo 

 size being the one generally adopted. In the smaller size the 

 species are entered in the first part of the index in systematic 

 order on the left-hand page, the right-hand page being reserved 

 for later additions. Then follows the alphabetical part, which 

 is written up across both pages on alternate lines, so as to allow 

 of any additional entries being made in their proper places. 



When the quarto page is used no detailed list is given of 

 the localities from which the examples have been derived. But 

 when the alphabetical list is made out, each page is indepen- 

 dent of the other, and runs on continuously, the alternate lines 

 being left for additional entries. 



It may be as well to put on record the principal sources 

 from which the plants have been derived. They are arranged 

 alphabetically, the British portion being separated from the 

 Continental, and both these from the exotic section. The dates 

 specified are either those of publication, or when they came into- 

 my possession. The list does not profess to be a complete one. 



