160 MOSSES AND LIVERWORTS 



a note can be made of the slides within, either by 

 reference to their numbers, or to the names of the 

 genera, according to the system of classification 

 adopted. And this leads me to say that the 

 cabinet may be arranged on one of two methods. 

 Some prefer to divide the drawer-space up accord- 

 ing to the different genera, in which case the 

 labels on the slides will contain such details as 

 the name and date and place of gathering. This 

 plan certainly has this advantage, that the keeping 

 of a separate register of slides may be dispensed 

 with, the slides themselves forming their own 

 register ; moreover, from its very nature, it ensures 

 that all the slides representing the various species 

 of a genus are kept side by side. But, on the 

 other hand, it is not nearly so economical of space, 

 and does not so easily lend itself to the duplication 

 of slides as does the arrangement according to 

 numbers. For, though the latter system involves 

 some considerable amount of trouble in the 

 systematic keeping of the necessary registers, yet, 

 as regards economy of space and otherwise, it 

 seems to me to have decided advantages. My plan 

 has been to have one general register of slides, 

 including both mosses and liverworts, in which 

 the various mounts are entered consecutively as 

 they are completed, each one opposite to its own 

 specific number, but without any regard either to 

 the tribe or genus to which each belongs. The 

 book is quarto size, and every page is ruled in four 



