54 THE PLANT WORLD. 



THE MAKING OF AN HERBARIUM. 



By WiLLARD N. Clutb. 



Fifth Paper. — ArraiKjing for use. 



After our plants have been properly mounted there conies the work 

 of arranging them in the herbarium in such manner that they 

 may be easily and quickly examined. If plants were assembled 

 without order or system, the larger the herbarium became the greater 

 would be the difficulty of finding a required specimen; but by a proper 

 arrangement it is possible to turn to any given specimen almost as 

 quickly as one would turn to a word in the dictionary. This l)eing the 

 case, it might be supposed that all our large herbariums are arranged 

 upon some uniform plan of this kind, but unfortunately most of them 

 are not. The botanist usual I v needs a guide book when visiting a 

 strange herbarium. 



In this day of identifying plants by comparisons with authentic 

 specimens, a merely alphabetical arrangement of families, genera and 

 species will not do, for the reason that this would almost certainly 

 separate closely related forms. In his studies, the botanist is saved an 

 infinite amount of time and labor if allied species are placed together. 

 But if they are so placed, one who is not acquainted with the systematic 

 arrangement of the species, may have much trouble in finding the half 

 dozen members of the genus with which he is familiar. Confusion, 

 therefore, is sure to exist when either the systematic or alphabetical 

 arrangement alone is followed. A combination of the two is much 

 the best. 



In order that all may understand the working of such a scheme, 

 let me sketch its application in the case of a large herbarium. Smaller 

 herbariums can modify the plan to suit their needs. In the ideal her- 

 barium, then, each species is placed as close to the next related species 

 as it is possible to do in a linear arrangement. The sequence now 

 generally followed is that of Engler and Prantl's "Pflanzenfamilien" 

 although there are still many herbariums arranged after systems long 

 out of date. Leaving out of the question lower forms of life, let us 

 assume that our herlxirium begins at the ferns and extends through all 

 the families of flowering plants to the highest, the composites. In 

 order to know where to find each family in this vast host, an index is 

 necessary. For this purpose the families are numbered in sequence, 



