MODERN BIOLOGY 381 



the institute Purkinje's interest in science began to wane; instead he applied 

 himself more and more to his country's culture and politics. Even in Breslau 

 he appeared as an author in the Czech language, translating the poems of 

 Schiller and Goethe into his native tongue. Having been called to Prague in 

 1850, he devoted himself heart and soul to the national cause; he now spelt 

 his name Jan Purkyne; he worked hard for the founding of a purely Czech 

 university and was a member of the Young Czech party in the Bohemian 

 Diet. National and foreign honours were showered upon him; and, wor- 

 shipped by his countrymen, though at the same time hated by the Germans 

 in his country, he laboured indefatigably to a great old age. He died in 1869. 



Purkinj".' s discoveries 

 PuRKiNjE is one of the great geniuses in the field of biological discovery; 

 a great number of facts of the highest value to our knowledge of life have 

 become known through him. On the other hand, he never systematically 

 and thoroughly investigated any particular field of inquiry, nor did he dis- 

 cuss theoretical problems. Even his greatest work, his investigations into 

 the physiology of the senses, is really only a collection of different experi- 

 ments and observations without any connexion other than the organ with 

 which they deal. His experiments on sight-physiology, the ideas for which, 

 as mentioned above, he obtained from Goethe's FarbenleJore, and which, in 

 fact, are dedicated to the poet, represent a work of fundamental importance 

 in their sphere. They were carried out with extraordinarily well-trained and 

 keen powers of observation and a corresponding gift for experiment. Visual 

 sensations induced by mechanical influence, by galvanic current, by various 

 kinds of light-impressions, are described and analysed; especially well known 

 are the chapters ' ' Indirektes Seben ' ' and ' ' Wabre und scbeitibare Bewegungen in 

 der Gesicbtssfbdre" ; famous, too, is the venous figure named after him, which 

 is caused by the oblique illumination of the eye. As a nicroscopist Purkinje 

 has likewise made remarkable discoveries, among which should be men- 

 tioned the germinal vesicle in the chick, discovered two years before von 

 Baer found the mammalian tgg; and, further, the spiral apertures of the 

 sweat-glands and the structure of cartilage. Of peculiar interest are the thor- 

 ough investigations into the existence of the cilia in the animal kingdom; 

 formerly these hairs were known only in protozoa and molluscs. Purkinje 

 discovered them and their movement in the oviduct and respiratory duct in 

 vertebrates — he established the movement's independence of any extra- 

 neous force, although, not yet being aware of the nature of the cell, he was 

 unable to adduce the latter's autonomous life as a cause of the phenomenon. 

 There is still one more of Purkinje's discoveries that deserves mention here — 

 namely, the axis cylinders of the nerves, and the large ramified cells in the 

 cerebellum, which bear his name. As a physiological chemist he became 

 known for his investigations into the effect of rennet on the digestive 



