20 i 



X. — Studies in Marine Biologjj. 

 By r. Martix Dltncax, F.IJ.P.S. 



Bead April 19, 1916. 

 Figs. 13, 14, 15. 



It was my intention to-night to have given some account of my 

 experiences in photographing, collecting, and preserving marine 

 biological specimens, but, as the hour is late, I will curtail my 

 remarks, and give a brief description of some of the photographs 

 exhibited on the screens and tables, and of some of the apparatus 

 used in obtaining them. The prints represent a small selection 

 from the very large collection of negatives which I have made 

 during the course of a good many years devoted to marine biological 

 studies, and I should like to say that a large number of them 

 could not liave been obtained but for the existence of the Marine 

 Biological Association of the United Kingdom, an institution 

 deserving the support of all microscopists who are in any way 

 interested in the teeming forms of microscopic life to be found in 

 the sea. 



I should like to draw your attention to this photomicrograph of 

 the Puerulus stage of Palinurus vulgaris, the Crawfish, or Lan- 

 gouste as it is called in France. It is of interest as the first 

 photomicrograph to be taken of the original specimen, discovered 

 by Monsieur E.-L. Bouvier, during his stay at the ]\Iarine Biological 

 Association's laboratory at Plymouth during the summer of 1913. 

 I happened to be carrying out some work in the Laboratory at the 

 time, and Monsieur Bouvier very kindly permitted me to take the 

 photomicrograph for him, and has used it to illustrate his paper on 

 the development of Paliimrus, published in the Journal of the 

 Marine Biological Association.* 



I should like also to draw your attention to the set of prints 

 showing some of the phases in the segmentation of the eggs of 

 Echinus esculentus, and which are printed from parts of a micro- 

 kinetograph negative obtained with a special form of apparatus I 

 have designed for taking kinetograph records of living microscopic 

 forms of life. In obtaining this interesting series of pictures I was 

 greatly assisted by my friend Dr. C res well Shearer, of Cambridge, 



* Journ. Mar. Biol. Assoc, x. No. 2, p. 179. 



