THE BIRTH OF HISTOLOGY 



175 



parliament. He assisted in molding the cell-theory into 

 better form, and in 1858 published a work on Cellular 

 Patlwlogy, which applied the cell-theory to diseased tissu- 

 It is to be remembered that Bichat was a medical man, in- 

 tensely interested in pathological, or diseased, tissues, and we 



Fig. 52. — Franz Leydig, 1821-1908. 



Courtesy of Dr. Wm. M. Wheeler. 



see in Virchow the one who especially extended Bichat's work 

 on the side of abnormal histology. Virchow's name is asso 

 ciated also with the beginning of the idea of germinal conti 

 nuity, which is the basis of biological ideas regarding hered- 

 ity (sec, further, Chapter XV). 



Leydig. — Franz Leydig (Fig. 52) was early in the field 

 as a histologist with his handbook (Lehrbuch der J I istolo. 



