THE VICTORIAN NATURALIST. 121 



be not kept every naturalist ought to keep an index of his 

 observations, for without it many are lost. I have kept a diary 

 since 1861, and though it is not consecutive — that is, there are 

 several periods, sometimes reaching to months, in one case to 

 years, in which no entries have been made — yet all of import- 

 ance are indexed, and I can at once refer to them. I use 

 Letts's No. 8 Diary ; it has a page for every day of the year, and 

 the faint lines do not interfere with any ink or coloured drawings. 

 At first I adhered to the dates at the head of the pages, but now 

 I use it as a simple MS. diary. It is of convenient size (7^ by 

 5 inches) for use and for the bookshelf If an object is too large to 

 draw in it I make a drawing on a larger piece of paper and insert 

 it, folding it up, as is done in many books with maps, &c. 



My experience in indexing has been as follows : — Before I 

 commenced the study of natural history in the field I procured 

 and used Todd's "Index Rerum," in which I indexed my reading 

 in various subjects ; this I subsequently used as an index to 

 my diary. An index of observations must necessarily be 

 different from an index to a book — in the latter everything is 

 entered in alphabetical order, in the former the entries must 

 be made one after the other as the observations are made. 

 The " Index Rerum " enables one in a great measure to minimize 

 the inconvenience of not having the entries in a truly alphabetical 

 order. As it may not be known to many of you I will describe 

 it. Primarily it is simply a ruled book with the letters of the 

 alphabet printed on the outside top corner of the pages, and 

 there are six leaves (not pages) for each letter, which I have used 

 in the way recommended — that is, to place the vowels a, e, i, 0, u, 

 and y on the top of leaves i, 2, 3, 4, 5, 6 respectively, belonging 

 to each letter. Every entry is made under the first letter of the 

 word and the first vowel in that word, thus : — Caladenia under 

 C, a ; Thelymitra under T, e; Dipodium under D, i ; Corysanthes 

 under C, ; Bursaria under B, u ; and Lyperanthus under L, y. 

 Of course in words beginning with a vowel the second one is the 

 guide, thus : — Acianthus under A, i ; Acacia under A, a, &c. 

 This subdivision of the letters into six divisions is very con- 

 venient, as, to find what you want, you have to look through at 

 most only one-sixth of the names that you would have to do were 

 not the letters subdivided. This system gives ample room for 

 the indexing of many years' observations, especially if the pages 

 are ruled into two columns, and letters can be continued into others 

 seldom used, as X, Y, Z. I have brought mine with me to-night, 

 and shall be happy to show it to any of the members. Though 

 commenced in 1857 they will see that there is room for several 

 years' more work, notwithstanding that now I have more leisure 

 my observations are consequently more numerous than formerly. 

 It is hardly necessary to say that the references in the index 

 may be either to the volume and page of the dairy or to the 



