SECTIONAL TRANSACTIONS.— D. 567 



end in different ways, and all occur in these swamps. In the cases of most of these 

 fishes the use of atmospheric air for respiration was previously known, but experiments 

 were performed with the object of determining the importance to them of this means 

 of aerating the blood and the structure of the accessory respiratory organs was 

 investigated. Adaptations to the same end were also found among the Oligochaetes. 

 Many planktonic forms were found to be able to survive in water of which the oxygen- 

 oontent was very low (-^S-'S c.c. per litre). 



The reasons for the shortage of oxygen in these waters were enquired into, and it 

 ia suggested that similar conditions occur widely in shallow tropical fresh waters. 



Mr. V. J. Clancey. — The Cinema in relation to Zoology (illustrated by 

 cinematograph films). 



The value of cinema to zoology lies in that it is a very reliable record of movements 

 in space and time. By virtue of the illusion of perspective, the motion picture gives 

 a good representation of action in three dimensional space — in fact, under certain 

 conditions stereoscopic effects may be obtained on the screen. The time scale may 

 be extended so that the action of one-hundredth or one-thousandth of a second 

 occupies a second or more on the screen, or it may be contracted so that the action of 

 hours or days may be shown in a few seconds. 



As an aid to research, cinema supplies a method for the repeated study of a move- 

 ment or set of movements and for arresting action at any point for further study. 

 The so-called ' slow motion ' and ' ultra-speed ' films show movements too rapid for 

 ordinary observation, while the * quick-motion ' films show those that are too slow. 

 Cinematography is applicable to all the uses of ordinary photography, such as colour 

 reproduction, photomicrography, and even the use of X-rays and ultra-violet light — 

 for high resolution of unstained tissues. 



If suitably edited, films may be used for showing results of experiments to specialised 

 workers, for elementary and technical education, for propaganda and for the instruction 

 of the general pubHo. 



(Examples are shown to indicate how these methods have been used in zoology.) 



Dr. M. Grabhaji. — Food Fishes of Madeira. 



Exhibits. 



Sister Monica (Dr. Monica Tayloe). — Methods for the Culture of 

 Amoeba and other common Laboratory Animals. 



Miss A. E. Miller. — The Structure of the Tail of Lepidosiren. 



Mr. R. A. Staig. — Exhibits from the Bishop Collection of Coleoptera and 

 other Collections of the Hunterian Museum. 



Dr. W. K. Spencer. — Starfish and Sea Urchins from the Palceozoic Rocks 



of Scotland. -^ " ;' " 



Mr. G. E. Hutchinson, Miss Grace E. Pickford, and Miss Johanna 

 F. M. Schuurman. — Natural History of the Transvaal Pans of South 

 Africa. 



Mr. C. W. Parsons. — Hearts of Fishes. 



Mr. G. S. Carter. — The Velar Ciliated Cells of Aeolidia papillosa. The 

 young of Lepidosiren. Fishes from the Swamps of the Paraguayan 

 Chaco. 



