264 BOTANICAL BIBLIOGRAPHY. 



a month or year (a favourite time with the editors), whereas the 

 part was not ready till the early portion of the following month or 

 year ; an excuse has been pleaded that from the nature of the case 

 it has been necessary some days in advance of the time of actual 

 publication to fix the date to be printed on the part, and that the 

 unforeseen delay of some days will occasionally occur. This excuse 

 fails and becomes untenable when, on the completion of the volume, 

 the same errors are repeated and reprinted, for at that time it is 

 positively known that some of the dates given are false ; it is 

 defensible only on the unprincipled ground that consistency and 

 firmness are more important and more desirable than truth and 



accuracy. 



Mr. B. Daydon Jackson has already in the 'Journal of Botany 1 

 alluded to a common trick that publishers have of post-dating 

 books : a case of this occurred with the first part of Peters' 

 Mozambique Botany, the date on the title-page of which is 1862; 

 but on consulting the preface of the second part it is learnt that 

 the former part really appeared at the close of the year 1861. 

 Mr. Jackson's researches, relating to the dates of Sir J. E. Smith's 

 articles in * Bees's Cyclopedia,' supplied a want previously much 

 felt, and for them the thanks of botanists are due to Mr. Jackson 

 and to the ' Journal of Botany.' 



The ' Botanical Magazine ' is usually quoted by the number of 

 the plate without reference to the volume ; the numbers of plates 

 contained in a volume and the intervals of time between the 

 completion of the volumes are not constant. A scheme, showing 

 the numbers of the plates published during each year since their 

 commencement in 1787, would be useful ; I have prepared one for 

 my private use, and could print it if thought necessary. 



In the case of those serial publications which have appeared 

 with some regularity throughout a long course of years, an 

 algebraical formula may be constructed, and would be useful to 

 those botanists who have not ready access to the complete work 

 and are not too much prejudiced against the employment of 

 anything like a mathematical expression. For example, take the 

 'Annales des Sciences Naturelles,' which consists of five series, 

 commencing in the year 1824. For the first series, the volumes, 

 whose number is expressed by 3n + l, 3n+2, 8n+8, bear the 

 date expressed by the formula 1824 +n ; for the subsequent series, 

 the number of the series being expressed by r+1, the volumes 

 whose number is expressed by 2n+l, 2w+2, bear the date 

 expressed by the formula 1824 + 10 r+w; this holds good up to 

 the tenth volume of the fifth series, the date of which is 1869 ; one 

 volume annually has been since published. 



In the case of the 'Journal of Botany,' the formula would give 

 for the nth volume of the original series the date of the year 

 expressed by 1862+n, and for the second series 1871 +n. 



