310 NATURAL SCIENCE. November, 



might not be out of place, although, no doubt, every collector has his 

 own method. 



Cardboard trays and loose labels are an abomination : delicate 

 specimens can be put in boxes with glass tops, and, in any case, every 

 specimen should have its own label fixed to it in some way. My plan 

 is to mount each specimen or series of specimens on a wooden tablet, 

 upon which is written the name, zone, exact locality, and a reference 

 to some accessible figure of the species. The tablets may be in mul- 

 tiples of each other. The best wood for making them is that of the 

 American poplar, known as American white-wood. This is soft enough 

 to allow thin pins to be driven in without bending, and firm enough to 

 prevent a heavy specimen from pushing the pins out of place. The 

 wood is covered with paper such as " Hieratica " or " Silurian," with 

 the aid of a spirit-gum known as " parlour paste " and a copying-press. 

 The edges of the paper should be trimmed off neatly with a round- 

 pointed knife. The specimens are attached to the mount by pins : 

 headless pins of any length or thickness may be obtained from D. F. 

 Tayler & Co., New Hall Works, George Street Parade, Birmingham. 

 Specimens that have to be examined with a lens, such as Bryozoa, 

 Foraminifera, and Entomostraca, should be kept under glass, since 

 they will rarely stand a second cleaning. Many collectors of Bryozoa 

 mount their specimens on wooden microscope slides with a circular 

 aperture backed by black paper. The plan has its advantages, but 

 the specimens get dirty, and their size is necessarily limited. I mount 

 Bryozoa on black cardboard slips, and enclose them in a glass tube 

 which is fixed with pins to a wooden mount on which the label 

 is written. The tubes that I use all have a length of ij ins. (about 

 31 mm.), with a diameter of ^ in. (3-5 mm.), ^ in. (12-5 mm.), and 

 -| in. (19 mm.) Tubes of this or other sizes may be bought by the 

 gross from Maw, Son & Thompson. If the surface of the cardboard 

 used is too greasy to take the gum, this can be remedied by rubbing 

 it with methylated ether. 



A cement is necessary for fixing small specimens to the tablets, 

 and for mounting broken ones. Fish-glue sometimes sinks into the 

 chalk, and, if the museum is at all damp, often causes mould to form 

 and the specimen to be detached. Gum and plaster of Paris is an 

 excellent cement, clean and strong, but the desideratum is something 

 which will set instantly, and will enable the specimen to be as readily 

 detached in case of need. Such a material is found in " dental model 

 cement," Avhich is probably a compound of shellac and white wax, 

 and is procurable at any dental depot at a cost of twopence a stick. 

 A spirit lamp is the only accessory. The value of the cement lies in 

 the fact that it is white and clean, always ready, and reasonably 

 strong ; and that anything as thin as a sixpenny-piece can be stuck up 

 on end on the mount, and very thin surfaces, such as the fragments of 

 an echinoderm, can be instantly fixed together. Moreover, large 

 masses of chalk may be at once cemented together, and the cement 



