MICROSCOPIC PREPARATIONS IN MARINE ZOOLOGY 327 



air bubble. When the cover is in place put two clips on, 

 one at each edge. If the clip bears on the centre of the 

 cover it will press it in, then when it is removed the cover 

 will reassert its level, and draw a bubble of air in under. 

 Entire objects of any kind larval stages of crustaceans, 

 young fishes, little annelids, etc. are mounted in the same 

 way, in sunk-cell slips. See that you have good, colourless 

 balsam for this, or it will show yellow in the deep part of 

 the cell, and look bad. 



Mounting Objects dry. In dry mounting the first thing 

 that suggests itself is what we mentioned, and saw how to 

 collect, in the first chapter viz. the Foraminifera. These 

 may be mounted mixed, as collected, or singled out and 

 duly labelled as types, which is the scientific plan. To pick 

 them out easily proceed thus. 



Have a piece of card, about four inches by two. Over this 

 stretch tightly a piece of black, corded silk (Gros de Naples), 

 and gum the edges underneath. On this bit of silk-covered 

 card put a pinch of the cleaned shells ; shake it a little, 

 and tilt it over sideways into a sheet of paper. 



Shells will remain in straight rows between the cords of 

 the silk, and the card and its burden can be placed on the 

 stage of the microscope, and " read off " without the 

 chance of missing one shell or the bother of twice going 

 over the same ones. 



Have a piece of black paper, lightly smeared with gum 

 arabic (very thin) and let dry, at hand. Now, while the 

 left hand moves the card about, in the right one hold a 

 bristle fastened to a little handle ; touch your forehead 

 with the bristle, then the desired foram. It will hold 

 lightly to the bristle, and can be lifted. Now breathe 

 on the gummed paper, and place the foram on it ; it will 

 stick. Thus they can be sorted out for instance, the 

 Lagenidce together, and so forth. In fact, this is a good 

 way of mounting slides right off. 



