OUTLINE OF BIOLOGICAL PROGRESS 2I 
Bichat, his great contemporary, created another by laying 
the foundation of our knowledge of the structure of animal 
tissues. 
Von Baer, by his studies of the development of animal 
life, supplied what was lacking in the work of Cuvier and 
Bichat and originated modern embryology. 
Haller, in the eighteenth, and Johannes Miiller in the 
nineteenth century, so added to the ground work of Harvey 
that physiology was made an independent subject and was 
established on modern lines. 
With Buffon, Erasmus Darwin, and Lamarck began an 
epoch in evolutionary thought which had its culminating 
point in the work of Charles Darwin. 
After Cuvier and Bichat came the establishing of the 
cell-theory, which created an epoch and influenced all 
further progress. 
Finally, through the discovery of protoplasm and the 
recognition that it is the seat of all vital activity, arrived the 
epoch which brought us fo the threshold of the biolog ey of 
the present day. 
Step by step naturalists have been led from the obvious 
and superficial facts about living organisms to the deep- 
lying basis of all vital manifestations. 
