CHAPTEK XVII 



MICROSCOPIC CHRONOPIJOTOGRAPHY 



Summary. — Various movements observable within the field of the 

 micro.-eope — Applications of chronophotography to the study of 

 these movements — Difficulties of the subject — Special arrange- 

 ment of the apparatus for ehronophctography on fixed plates and 

 on moving films — Retraction of the stalk in vorticella — Move- 

 ment of the blood in capillary vessels — Movements of the zoo- 

 spores in the cells of conferva — The use of the solar microscope 

 in chronophotography — The easy application of this method. 



The microscope has been found of use in all branches 

 of natural science, and by it the observer can fathom 

 the minutest structural details of an organ, and can 

 study in certain of their component cells movements 

 which are the very essence of their activity. 



Although Harvey, by a flight of genius, concluded 

 that arterial blood returned in some sort of way by 

 the veins, the actual demonstration of this passage 

 was not effected until the invention of the microscope. 

 The whole secret was then suddenly revealed to the 

 astonished eyes of Jlalpighi — the presence of corpuscles 

 in the plasma of the blood, the capillary ramifications 

 of the vessels which contained it, and the vagarious 

 current which left the arteries and effected its return 

 by way of the veins. 



The contraction of muscles was inexplicable until 

 the use of the microscope revealed the existence of 

 muscular fibres, their shortening by means of an 

 aggregation of the component discs, and the wave 



