Studies in Marine Biology. Bij F. M. Duncan. 



259 



liave been made on the Ortho A, B, or C plates manufactured by 

 M. M. Lumiere, and the very fine chromatic and panchromatic 

 plates of the Ilford Company. For obtaining natural colour photo- 

 graphs of the subjects, I consider that the beautiful Lumiere auto- 

 chrome plate is the only direct colour-plate that will faithfully 

 render the object with all its true tints. Eor all photomicro- 

 graphic work backed isochromatic or panchromatic plates should 

 be used. 



In photographing the larger forms of marine animals, either 

 in the rock-pools or in the special tanks, a good Eeflex camera, 



Fig. 14. — Showing the upright support for the Verascope Camera 

 drawn back, leaving the Eye-pieces of the Stereo-binocular 

 Microscope free for focusing the specimen. 



such as the Xewman and Guardia model, which I have now 

 used for many years, will be found invahiable, as enabling one to 

 watch and keep the animal in focus up to the moment of exposing 

 the plate. Sky reflections are often a great trouble when work- 

 ing in the rock-pools, and I have found a light metal cone, that can 

 be attached either to the front of the camera, or to a stand, so that 

 one end is beneath the surface of the water — practically a water- 

 telescope — a simple and certain way of avoiding surface reflections. 

 One of the great difficulties one has to contend with is the sensi- 

 tiveness of all marine creatures to change of temperature, a rise 

 of only a few degrees being quite enough to produce very marked 

 effects, particularly with many plankton forms, Hydroids, etc. 



