166 Professor WiUiiim Stirling [May 12, 



WEEKLY EVENING MEETING, 



Friday, May 12, 1911. 



His Grace The Duke of Northumberland, K.G. P.O. D.C.L. 

 LL.D. F.K.S., President, in the Chair. 



Professor William Stirling, M.D. LL.D. D.Sc. 



Biology and the Cinematograph. 

 [with illustratioks.] 



We are but children of a larger growth — direct descendants of 

 " Helen's Babies " and their predecessors. Some of you may 

 remember that " Helen's Babies " more than three decades ago 

 wished to see the wheels go round — they were not content with a 

 glance at the dial of the three hundred dollar timekeeper of their 

 long-suffering uncle. Humanity of older growth is still trying to 

 look beyond the dial. It also wishes to see tlie wheels go round. 



Movement is one of the most characteristic signs of active life — 

 although it is not peculiar to or distinctive of animal life — but as 

 animals possess in the highest degree the power of generating 

 mechanical motion, naturally their motor organs have been far more 

 carefully investigated than the movements themselves, and the 

 reason is not far to seek. Progress in the intimate study of animal 

 movements is being made, as it becomes daily more apparent how 

 infinitely fertile are the movements of organisms as a field for the 

 study of adapted actions. I include amongst these actions all those 

 movements which have been investigated with such conspicuous 

 success by Jennings, of Philadelphia, under the title " Behaviour of 

 Animals." 



Borelli, " De Motu Aiiinmliam.'" 



On the last day of the year 1678, and as the new year w^as coming 

 in, there died in the Convent of San Pantaleone, in Eome, Giovanni 

 Alfonso Borelli, the founder of the study of animal movement and 

 the teacher of Marcellus Malpighi. Borelli, in his classical work, 

 " De Motu Animalium," published after his death, deals not only 

 with the external visible movements of animals, but also with move- 

 ments of internal organs, such as the heart, the gizzard of birds, and 

 the swimming bladder of a fish. Marey points out that he even 

 gave the first correct explanation of the flight of a bird. Such 

 analyses of animal movements as Borelli did make were made by 

 means of the unaided eye. 



