19° BIOLOGY AND ITS MAKERS 



which Muller himself had filled in the University of Berlin, 

 and during the period of his vigor was in physiology one of 

 the lights of the world. It is no uncommon thing to find 

 recently published physiologies dedicated either to the mem- 

 ory of Johannes Muller, as in the case of that remarkable 

 General Physiology by Verworn; or to Ludwig, or to Du 

 Bois-Reymond, who were in part his intellectual product. 

 From this disposition among physiologists to do homage to 

 Muller, we are able to estimate somewhat more closely the 

 tremendous reach of his influence. 



Bernard. — When Muller was twelve years old there was 

 born in Saint- Julien, department of the Rhone, Claude 

 Bernard, who attained an eminence as a physiologist, of which 

 the French nation are justly proud. Although he was little 

 thought of as a student, nevertheless after he came under the 

 influence of Magendie, at the age of twenty-six, he developed 

 rapidly and showed his true metal. Fie exhibited great 

 manual dexterity in performing experiments, and also a 

 luminous quality of mind in interpreting his observations. 

 One of his greatest achievements in physiology was the dis- 

 covery of the formation within the liver of glycogen, a sub- 

 stance chemically related to sugar. Later he discovered the 

 system of vaso-motor nerves that control and regulate the 

 caliber of the blood-vessels. Both of these discoveries as- 

 sisted materially in understanding the wonderful changes 

 that are going on within the human body. But besides his 

 technical researches, any special consideration of which lies 

 quite beyond the purpose of this book, he published in 1878- 

 1879 a work upon the phenomena of life in animals and 

 vegetables, a work that had general influence in extending 

 the knowledge of vital activities. I refer to his now classic 

 Legons stir les Plienomenes de la vie commims mix animaux et 

 aux vegetaux. 



The thoughtful face of Bernard is shown in his portrait. 



