[ ix ] 



W. J. Hooker large additions have continued to be made to the herbarium ; 

 and it now consists of more than 2,000,000 specimens, and is the recognised 

 official depository of all botanic collections acquired through Government 

 expeditions. 



In a herbarium specimens may be present which are the actual plants Relative value of 

 made use of in the description of new species by the authors of those species. ^^^ two Herbaria. 

 Such specimens, usually spoken of as " type specimens," have a value of a 

 different order from that of other specimens, and a herbarium may, in general 

 terms, be spoken of as more or less valuable according to the number of 

 " type specimens " which it contains. OAving to its mode of origin the 

 General Herbarium of the Britisli Museum is of special value inasmuch as it 

 contains the " type specimens " of the Banksian Herbarium. It is also of 

 value, though of less value, by reason of the type specimens contained in the 

 collections acquired since 1827 ; the additions to it since the transference to 

 Cromwell Road contain many " type specimens," but the increase in such 

 specimens has not been proportionate to the general increase. The pre- 

 Linnean Sloane Herbaria are mainly of value for antiquarian or historical 

 researches, and the value of the British Herbarium lies chiefly in the 

 convenience which it offers for all enquiries limited to British plants. 



The Herbarium of the Royal Botanic Gardens at Kcav has, on the other 

 hand, a special value on account of its being very rich in type specimens of a 

 date posterior to that of the Banksian Herbarium, more particularly of the 

 plants of India and of the British Colonies and Possessions. In all these it 

 is far richer than the Herbarium at the Britisli Museum, so much so that, as 

 a rule, botanists engaged in researches in systematic l)0tany find it profitable 

 to work at Kew in the first instance, visiting the British Museum 

 subsequentl}^ 



From the manner in which the two collections have grown up it is Duplication of 

 natm^al that verv manv of the specimens contained in the one collection specimens in the 



J TT 1 



are exact and undoubted duplicates of specimens contained in the neroana. 

 other collection. It may here be noted that the question of "duplicates" 

 is a vexed one among botanists ; opinions may vary in respect to a 

 particular specimen, whether it is or it is not a duplicate of another 

 specimen, and may vary as to the extent to which so-called duplicates ought 

 to be retained. But, making every allowance for such difference of opinions, 

 it may with safety be asserted that the two collections contain a very large 

 numlDer of duplicates, which, were the two collections merged into one, could 

 serve no scientific purpose, and would certainly not be retained. The dupli- 

 cation of books in the two libraries which are attached, one to each 

 herbarium, is of course absolute. 



The real duplication of siDCcimens between the two herbaria, which 

 seems to have especially increased since the transference from Bloom sbury 

 to Cromwell Road, entails duplication not only of room for housing, and of 

 ordina^ry menial attendance and caretaking, but also of scientific work and 

 hence of scientific staff. In the case of each collection, every new specimen 

 added has to be examined by a member of the scientific staff, verified or 

 described by him, catalogued by him, and "laid in" by him in its appropriate 

 place in the herbarium ; and members of the staff have also between them 

 the fm^ther duty of repeatedly examining or supervising the whole collection 

 in order that its efficiency may be maintained. Hence each actual duplicate 

 of the two collections entails, both upon the addition of the specimen to 

 the collection and during its remaining in the collection, a certain amount of 

 scientific work, a certain labour on the part of the scientific staff, which 

 serves no real scientific j)urpose at all ; the duplication is the cause of a 

 scientific waste. 



The existence of this waste, considered by itself, fuinishes an argu- Duplication an 

 ment against the two collections being maintained as thev i' re maintained at ^^'gument agamst 



f^ 1 • o J? p F • !• A.^ J. " maintenance m 



present and m favour oi some form of union of the tAvo. present form. 



• 5036. b 



