1788 



Journal of Applied Microscopy 



is done. With a direct and rigid connection between the metal focusing rod and 

 the coarse adjustment injury might result to the microscope. 



This method of focusing the microscope by means of the coarse adjustment 

 is to be preferred for all work with very low powers. Not only is it more rapid 

 but the rapid focusing enables one to tell with much greater certainty when the 

 object is actually in focus. With the slower movement of the fine adjustment 



Fig. 6. — Argulns Sp. Ventral View ; photographed under alcohol ; B. & L. 

 Zeiss 3-in. microplanar ; stop V- : bellows length 70 cm.; lighted by arc 

 lamp. Seed's non-halation plate, 70s. exposure. Bromo-hydrochinone 

 developer, x 10. 



one is often uncertain. If high powers are to be used, the focusing rod and 

 Hooke's key provided with the camera may be attached to the limb of the cross 

 bar, opposite that which carries the pulleys, and by means of these the fine 

 adjustment may be turned from a distance. 



The method of using the apparatus for photographing small opaque objects such 

 as vertebrate embryos is as follows : The apparatus is set up as described 



