THE PHYSICAL BASIS OF LIFE 263 



is usually credited with being the discoverer of protoplasm. 

 His researches, moreover, were closely connected with the 

 development of the ideas regarding the r61e played in nature 

 by this living substance. 



Dujardin was a quiet modest man, whose attainments and 

 service to the progress of biology have usually been under- 

 rated. He was born in 1801 at Tours, and died in 1860 at 

 Rennes. Being descended from a race of watchmakers, he 

 received in his youth a training in that craft which cultivated 

 his natural manual dexterity, and, later, this assisted him in 

 his manipulations of the microscope. He had a fondness for 

 sketching, and produced some miniatures and other works 

 of art that showed great merit. His use of colors was very 

 effective, and in 1818 he went to Paris for the purpose of 

 perfecting himself in painting, and with the intention of 

 becoming an artist. The small financial returns, however, 

 "led him to accept work as an engineer directing the con- 

 struction of hydraulic work in Sedan." He had already 

 shown a love for natural science, and this led him from engin- 

 eering into work as a librarian and then as a teacher. He 

 made field observations in geology and botany, and com- 

 menced publication in those departments of science. 



About 1834 he began to devote his chief efforts to 

 microscopic work, toward which he had a strong inclination, 

 and from that time on he became a zoologist, with a steadily 

 growing recognition for high-class observation. Besides his 

 technical scientific papers, he wrote in a popular vein to 

 increase his income. Among his writings of this type may be 

 mentioned as occupying high rank his charmingly written 

 "Rambles of a Naturalist" (Promenades (Tun Naturaliste, 

 1838). 



By 1840 he had established such a good record as a sci- 

 entific investigator that he was called to the newly founded 

 University of Rennes as dean of the faculty. He found him- 



