56 HAECKEL 



microscopic discovery that the more powerful 

 lenses and the improved methods of research were 

 only gradually introduced, and enabled students 

 to found a new and much profounder anatomy. 

 As soon as this science appeared it was given 

 the special name of '^ histology," or the science 

 of the tissues (hista). Its particular achievement 

 is the discovery that in man, the animal, and 

 the plant, all the parts of the body prove, when 

 sufficiently magnified, to be composed of small 

 living elements, which are known as cells. The 

 discovery of the cell was made in the latter part 

 of the third decade of the nineteenth century. 

 These cells join together in homogeneous groups 

 in order to accomplish one or other function in the 

 body, and thus form its '' tissues." Their intricate 

 structure is unravelled by the histologist, micro- 

 scope in hand. It is evident that in this way 

 a new basis was provided for anatomy, and there- 

 fore also for medicine. In the fifties Wiirtzburg 

 was the leading school of histology, or the science 

 of these tissues composed of cells. Albert Kolliker, 

 professor of anatomy there since 1847, published 

 his splendid Manual of Histology at the very time 

 when Haeckel was studying under him. Franz 

 Leydig, a tutor there since 1849, was working 

 in the same direction. The third member of the 

 group, made professor in 1849, was Eudolf 

 Virchow, a young teacher then in his best years. 

 It was Yirchow who did most to bring practical 

 medicine into line with histology. As the vital 

 processes in the human body seemed to him, with 



