24 FORAMINIFERA 



with their danger of retaining specimens, the plate alone may 

 be used on the stage of the microscope. 



The selected specimens may be mounted on slides directly or 

 may be sorted to families and genera for further study. In 

 picking out the specimens, the best method is to use a moistened 

 brush. The finest brushes obtainable, 00 size, made of red sable 

 bristles are by far the best. These make a very fine point indeed 

 and, if moistened and touched to the specimen can be used to 

 carry it to the slide. Needles are sometimes used but they are 

 not elastic, do not retain moisture, and easily break delicate 

 specimens. Camel's hair brushes are not sufficiently elastic to 

 be of much service. The sable brushes if left moistened and 

 the tip drawn to a point will last for a long time. 



It is necessary to mount the selected material for safety for 

 further study and for permanent preservation. Slides of vari- 

 ous sorts are used. One of the simplest, cheapest, and most 

 generally satisfactory types of slide is made of two pieces of 

 pasteboard, the upper of good grade and thick, the bottom one 

 of cheaper grade and thinner. The upper one is punched with 

 holes of the desired size and number, and between the two a 

 piece of black paper inserted. The two then are pasted with 

 Map Mounter's Paste which is very strong. To avoid the black 

 paper, the lower piece may be made of black surfaced heavy 

 paper or be covered with various black waterproof substances. 



For slides of individual species, it is best to have a slide with 

 a single opening, preferably centered, and not over a half-inch 

 in diameter. This then leaves plenty of room for labelling and 

 for cover. A very simple method is to place an ordinary cover 

 glass above the opening with a tiny drop of glue at three or 

 four places near the edge. The point of a knife or needle will 

 quickly snap off the cover if it is necessary to change the posi- 

 tion of the specimens for further study. A neater method of 

 cover is that provided by a sheath made of a glass slide and a 

 base of a thin strip of cardboard, the two attached by strips of 

 gummed paper at the sides. For the study of faunas, it is often 

 useful to have slides with several rows of small openings into 

 which may be put different species from the same sample. 

 These may have the glass sheath. There are various types of 

 pasteboard slides on the market which are very cheap but that 

 is their chief recommendation. As a rule they are of too poor 



