AT THE UNIYEKSITY 57 



his strict histological outlook, to be traced back 

 always to the tissue-building cells, he concluded 

 that disease also, or the pathological condition 

 of the body, and therefore the proper field of the 

 medical man, was a process in these cells. Man 

 seemed to him to be a " cell-state " : the tissues 

 were the various active social strata in this state : 

 and disease was, in its ultimate source, a conflict 

 in the state between the citizens, the tissue- 

 forming cells, that normally divide the work 

 amongst them for the common good. Pathology 

 must be cellular pathology. The science was 

 already being taught by Virchow at Wiirtzburg, 

 and the dry bones of it were covered with flesh 

 for his hearers. But his ideas were not published 

 until a few years afterwards (1858). 



In the first three terms Haeckel studied chiefly 

 under Kolliker and Leydig. They taught him 

 animal and human embryology, as it was then 

 conceived. Embryology was the science of the 

 development of the individual animal or man, 

 the description of the series of changes that the 

 chick passes through in the egg or the human 

 embryo in the womb. This science, also, had 

 been profoundly affected by the invention of the 

 microscope. Firstly, the spermatozoa, the active, 

 microscopically small particles in the animal and 

 human sperm, had been discovered. Then, in 

 the twenties, Karl Ernst von Baer had discovered 

 the human ovum. The relation of these things 

 to the cell-theory was clear. It was indubitable 

 that each of these male spermatozoa and each 



