1911] 0)1 Biolofiy and tlio Cinematograph. 17;") 



bichromate of potash aud sulphuric acid, the mercury bes^ins to pulsate 

 or beat rhythmically in the most re,2:ular manner — a phenomenon de- 

 scribed in this form by Ostwald and hence called " Ostwald's Physical 

 Heart." This phenomenon is also due to alteration of surface tension. 

 The beats arc seen witli irreat distinctness in the cinematograpli tihn. 



Ciliary Motion and what it can do. 



The movements of cilia were shown by means of a Stroboscope, 

 so that the audience could follow the movements of the individual 

 ciUa — both when moving slowly and when vibrating quickly, as it 

 were under the influence of heat. 



To illustrate what ciliary action can do in the way of transport, 

 the head of a dead brainless frog with the lower jaw removed was 

 shown. On the front of the palate was placed a large piece of the 

 animal's liver and on this a small flag. Liver and flag were seen to 

 be rapidly carried downwards right into the gullet of the frog. The 

 experiment illustrates the large amount of work that can be done by 

 the combined co-ordinated action of thousands of these microscopic 

 vibratile hairs called cilia, and also their importance in the removal of 

 secretions and particles from the passage which they line. 



Alovements of Starfish and Sea Urchins. 



The movements of the tube feet of various Echinoderms and the 

 movements of the animals themselves have been carefully studied by 

 Preyer, Romanes, Uexkiill, Loeb, Jennings, and others. 



Some of the starfish, such as Astropecten, rapidly bury themselves 

 in the sand. A film showing this process was exhibited. 



Starfish in Confined Space. 



The movements of a starfish placed on its back and gradually 

 "righting" itself were shown, but a more interesting phenomenon 

 is to watch the movements of the tube feet and arms of a starfish 

 placed on its back in a confined space, until it finally succeeds 

 in righting itself and arranging itself in the vessel on its ventral 

 surface. 



Jennings has carefully studied these movements, as well as the 

 movements of the tube feet of a starfish catching a fish or a crab. 

 SUdes to illustrate these remarkable modes of capturing prey were 

 shown. 



Sea Urchin — J'uhe Feet and Pedicellaria. 



The movements of the tube feet of a sea urchin in water were 

 also shown, and in the same animal the movements of its pedicellaria 

 as well as those of " Aristotle's lantern " could be distinctly seen. 



