292 MOVEMENT 



that travelled along the length of the fibre during 

 the act of contraction. Since that time physiologists 

 have no longer gone astray after hypothetical "veins"; 

 it is in the actual fibres of the muscles that they seek 

 the origin of mechanical energy in animals. 



Facts accumulate — little by little the theory un- 

 folds itself, and the moment is felt to be fast 

 approaching when muscular contraction will be a fully 

 explained fact. 



The microscope shows us in a drop of water the 

 animate motion of a million minute organisms roaming 

 about with curious modes of locomotion — methods 

 which find no counterpart among the more highly 

 developed animals. 



The pulsation of the heart can be seen through the 

 transparent integuments of certain larvae ; so, too, can 

 the contraction of the intestine, the curious phenomena 

 connected with generation, and the slow metamorphosis 

 of the ovum or the embryo. 



The chemist himself, as he watches the beautiful 

 crystalline arborizations developing upon the micro- 

 scopic slide, essays to interpret the laws of this 

 mysterious architecture. 



All these movements, however slow or however rapid 

 be the process, can be followed in their respective 

 phases by means of successive photographs, no less 

 clearly than they can be viewed under the microscope. 



Applications of Chronophotography to the Study of 

 these Movements within the Field of this Microscope. — 

 Our own instrument is the only one up till now which 

 can be used for taking a photographic series of micro- 

 scopical objects. Since our instrument is only pro- 

 vided with one object-glass, the latter must be of 

 suitable focal length for forming images on the 

 sensitized plate of such a nature that they can be 

 enlarged to any degree. The process of microphoto- 



