26 FORAMINIFERA 



a tnm coating can be placed directly on the slide and allowed to 

 dry. The moisture from the brush as the specimen is trans- 

 ferred will soften the gum sufficiently so that the specimen will 

 become attached, and before drying, the specimen can be oriented 

 to the desired position. A very little gum should be used so as 

 not to cover important structures and for ease in removing the 

 specimen if desired. 



Some workers prefer to use glass slides with concave cells 

 placing the specimens in these under an ordinary cover glass. 

 These have the difficulty of the specimens getting lodged be- 

 tween the cover and the slide, and thus becoming broken. The 

 slides themselves are easily broken and must have some sort 

 of label attached whereas the cardboard slides can be written 

 upon directly. 



In studying and drawing specimens, it is often necessary to 

 place them in different positions. Ordinary plasticene can be 

 used, preferably dark colored sorts. This is sticky however, 

 and it is often difficult to clean specimens. A better material 

 is the black wax used in biological laboratories for making 

 models from serial sections. It is easily softened with the 

 warmth of the hand, and is not sticky, A hole may be made 

 with the point of a needle and the specimen set in it, or often 

 simply stood on end on the wax itself. Far better than either 

 of the above in my own work is the Prism Rotator. With this 

 simple device, it is possible to study the specimen without mov- 

 ing it, and to get views from above and below. The entire 

 periphery may be viewed from every angle by rotating the 

 prism. It is invaluable for full study of specimens especially 

 if one wishes to view the aperture from all angles to see the 

 different aspects. For drawing this may be used with the 

 ordinary camera-lucida and all views made without touching 

 the specimen. For measuring specimens this is also invaluable 

 for with an ocular micrometer, the various dimensions may be 

 obtained without disturbing the specimen. 



In the study of dry specimens, it will often be found that 

 moistening the exterior will bring out the structure very dis- 

 tinctly. This may be done with water or if a long study is 

 needed in drawing, glycerin will dry less rapidly. 



Photography is very useful in the study of specimens and 

 making permanent records. The methods in use in this labora- 



